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Non ethanol fuel question

#1

R

Rickcin

The new Sheetz gas station near our house happens to sell ethanol free fuel, however the octane rating seems to be 90 (instead of the usual 87)
Is this higher octane safe for my Kohler VTwinand for my Honda self propelled mower?


#2

ILENGINE

ILENGINE

Yes. The only gas I have in the shop either is 91 non-ethanol or 93 with 10%.


#3

G

GearHead36

The octane rating for your engine is a minimum. You can go higher with no problem, except for expense. The high octane (especially ethanol-free) will be more expensive.


#4

R

Rickcin

The octane rating for your engine is a minimum. You can go higher with no problem, except for expense. The high octane (especially ethanol-free) will be more expensive.
The reason for my question was because when reading up on using a higher octane in small engines, one article said it can cause small engines to run hotter and possibly cause damage to the valves.


#5

ILENGINE

ILENGINE

The reason for my question was because when reading up on using a higher octane in small engines, one article said it can cause small engines to run hotter and possibly cause damage to the valves.
All of the premium small 2 stroke manufacturers, aka Stihl Husqvarna, Makita/Dolmar require a minimum of 90+ in their products to prevent pre-ignition which will cause engine damage. But premium fuel doesn't burn any hotter than non-premium fuel because it has the same btu rating. The only disadvantage is the higher cost to operate because in most cases will not change your fuel usage.

And my personal opinion is premium stores better, but that may just be my opinion and could be incorrect.


#6

TonyPrin

TonyPrin

The reason for my question was because when reading up on using a higher octane in small engines, one article said it can cause small engines to run hotter and possibly cause damage to the valves.
There are several impacts higher than recommended octane can have on a small engine, all negative. Higher octane can make the engine harder to start, run harder and hotter. I'd be careful about using higher octane fuel for long periods (perhaps over 30 minutes) without allowing the engine to cool. The negative impact of higher impact fuels is due to the slower burn rate they produce.


#7

ILENGINE

ILENGINE

There are several impacts higher than recommended octane can have on a small engine, all negative. Higher octane can make the engine harder to start, run harder and hotter. I'd be careful about using higher octane fuel for long periods (perhaps over 30 minutes) without allowing the engine to cool. The negative impact of higher impact fuels is due to the slower burn rate they produce.
And everything you just posted has been proven false. Some of it may of been considered true years ago, but with current fuel formulation is all false. Higher octane reduced pre-ignition but has the same burn rate and btu output as 87 octane.


#8

TonyPrin

TonyPrin

And everything you just posted has been proven false. Some of it may of been considered true years ago, but with current fuel formulation is all false. Higher octane reduced pre-ignition but has the same burn rate and btu output as 87 octane.
I try to give my opinion without saying other views are false unless I can prove it. If what I say has been "proven" false as ILENGINE posts, don't just say so. Prove it.

I'm not an expert on gasoline but am fairly knowledgeable. It's well established that octane rating is a measure of gasoline stability; a higher octane is more stable than a lower octane. Octane is determined by the pressure at which the gasoline spontaneously combusts. Engines are designed to operate at a specific compression and octane. When an octane used is different than the octane for which the engine is designed, the gasoline will either ignite earlier, later, or incompletely. Car engines requiring high octane gasoline typically have a compression of 200 psi or more while small engines are closer to 100 psi. Thus, high octane gasoline is likely to combust incompletely in a small engine. Note that virtually all new cars can run on high octane gasoline due to electronic ignition advances.

And burn rate is the speed at which a gasoline mixture burns. That all being the case, how can gasolines that are more or less stable and combust at different pressures have the same burn rate, i.e., rate of speed? And why doesn't incomplete combustion lead to engine issues?


#9

S

Skippydiesel

Like you Tony I am no expert on fuel standards or performance.

I am with ILENGINI on this matter.

I can not speak for USA fuels however here in Australia we commonly have 91,95 & 98 RON (Research Octane Number). I don't use ethanol blends so won't comment on them.
91 RON is used in small motors and lower performing vehicles. Is the cheapest, non ethanol, fuel
98 RON is used in high performance engines. Is the most expensive petrol
Octane rating is a measure of the anti knock (pre ignition) characteristics of the fuel. The higher the compression ratio of the engine, the more need for anti knock.
Our 98 RON does not store well in a container (fuel tank) that is open to atmosphere, some of its volatile fractions will be lost resulting in difficult starting. There is also a tendency for the old fuel to more readily "gum" up the smaller jets in the fuel metering system.
91 RON seems to stay "good" for very many months without much loss of quality ie from a users standpoint, is more stable retaining its performance characteristics longer than 98.
Using 98 in an engine designed (lower compression) for 91 will result in no benefit OR DAMAGE other than to your pocket.
Using 91 in an engine designed to run on 98 (high compression) will likely lead to loss of power & internal damage to the engine. Symptoms are likely to be a rattling sound (knock) when engine under load and the engine may "run on" after the ignition turned off.


#10

TonyPrin

TonyPrin

Like you Tony I am no expert on fuel standards or performance.

I am with ILENGINI on this matter.

I can not speak for USA fuels however here in Australia we commonly have 91,95 & 98 RON (Research Octane Number). I don't use ethanol blends so won't comment on them.
91 RON is used in small motors and lower performing vehicles. Is the cheapest, non ethanol, fuel
98 RON is used in high performance engines.
Skippydiesel, in the interest of space I only quoted a portion of your post. I guess the time difference allowed you to jump in on while we were dosing. I'm sorry you said you didn't agree with me, but your post seems to confirm what I said so I'm hoping you'll switch sides.

The issue is whether high octane fuel can damage a small engine. Per the post, "91 RON is used in small motors and lower performing vehicles" in Australia. In the USA, the octane rating is a combination of RON and MON which calculates to 4-5 points lower than RON alone. Thus, 91 RON is the same as 87 octane. So, when 91 RON is used in small engines in Australia, you're using USA 87 octane, consistent with my earlier post.


#11

ILENGINE

ILENGINE

VP racing small engine fuel is 94 octane


Trufuel says theirs is high octane with several references to 92+


Aspen fuel says theirs is also 92+


So if high octane is bad for small engines then why do all the canned fuel manufacturers have high octane fuel that you claim will burn hotter and damage small engines instead of 87.


#12

R

Rickcin

Skippydiesel, in the interest of space I only quoted a portion of your post. I guess the time difference allowed you to jump in on while we were dosing. I'm sorry you said you didn't agree with me, but your post seems to confirm what I said so I'm hoping you'll switch sides.

The issue is whether high octane fuel can damage a small engine. Per the post, "91 RON is used in small motors and lower performing vehicles" in Australia. In the USA, the octane rating is a combination of RON and MON which calculates to 4-5 points lower than RON alone. Thus, 91 RON is the same as 87 octane. So, when 91 RON is used in small engines in Australia, you're using USA 87 octane, consistent with my earlier post.
So I guess my original post had some validity but my concern still is as follows;
If the available ethanol free fuel is 91 octane, is it safe to use that or should I mix a little normal fuel (10% ethanol) to dilute the octane rating?

Another point of interest is that since most service stations have 4 different grades of gas with a common hose and nozzle, whenever we make a selection to pump gas, we are going to first receive the fuel that’s in the hose from the last user. The valve to that controls the flow is in the pump, not all the way back to the tank.

I realize it’s only a small amount of fuel, however if you were filling a 1 or 2.5 gallon container, it would be a significant percentage.
One way around this would be to first pump of your fuel of choice into your vehicle so that you get 100 percent of your desired fuel for your mowers or small engines.


#13

Hammermechanicman

Hammermechanicman

All of the premium small 2 stroke manufacturers, aka Stihl Husqvarna, Makita/Dolmar require a minimum of 90+ in their products to prevent pre-ignition which will cause engine damage. But premium fuel doesn't burn any hotter than non-premium fuel because it has the same btu rating.
All the saw mfgrs say to use 90+ rated fuel or it will damage the saw. I don't think so. I have serviced over a hundred customer saws run on regular 87 E10 gas. Never seen one damaged from preignition. I have 5 saws that all run on regular E10. Two of them are stihl clones a 361 and a 660. Both of those are ported and run about 190psi compression and advanced timing. After dozens of tanks of fuel usually run with the 25" bar buried in ash haven't seen a preignition issue.


#14

TonyPrin

TonyPrin

So if high octane is bad for small engines then why do all the canned fuel manufacturers have high octane fuel that you claim will burn hotter and damage small engines instead of 87.
For the same reason any business does anything. The fact a business sells something doesn't make it good to use.

I go back to what I said before. High octane gasoline is designed to combust at 50% or more above small engine compression psi. That has to mean high octane fuels will not fully combust in small engines leading to engine issues. Likewise, low octane fuels can lead to detonation (knocking) in high compression engines. Those issues have been resolved in cars due to computerized sensing but still applies to small engines without sophisticated computers.


#15

Hammermechanicman

Hammermechanicman

The burn rate difference between 87 and 92 is negligible in stock small engines. We are not doing max HP pulls on a dyno.

Has anyone seen a small engine damaged from preignition?


#16

TonyPrin

TonyPrin

Has anyone seen a small engine damaged from preignition?
The issue isn't preignition; it's incomplete or partial combustion. High octane fuels are designed to combust at a much higher compression than small engines produce, on average around double.


#17

ILENGINE

ILENGINE

The issue isn't preignition; it's incomplete or partial combustion. High octane fuels are designed to combust at a much higher compression than small engines produce, on average around double.
I guess it comes down to what you consider high compression 9:1, 10:1 or more.


#18

TonyPrin

TonyPrin

I guess it comes down to what you consider high compression 9:1, 10:1 or more.
Typical BMW compression ratio is 10:1 or higher, while B&S is 6:1.


#19

ILENGINE

ILENGINE

Typical BMW compression ratio is 10:1 or higher, while B&S is 6:1.
The Briggs Vanguard is 8.5:1 Stihl, Husqvarna, Dolmar/Makita all have products in the 10:1+ category. The Kohler Command twin since it has a minimum compression of 160 would be in the 11-12:1 range.


#20

Hammermechanicman

Hammermechanicman

The issue isn't preignition; it's incomplete or partial combustion. High octane fuels are designed to combust at a much higher compression than small engines produce, on average around double.
High octane fuels are harder to ignite BUT once ignited they burn slightly slower than lower octane rated fuels. In a 4 stroke engine running 3600 RPM the difference is negligible if even measurable. In hopped up 2 stroke chainsaws running 13000+ RPM doing max pulls in wood guys have seen a difference in fuels. A spark plug can ignite 93 just as easy 87 regardless of compression ratio. Putting 93 vs 87 in outdoor power equipment will not cause partial or incomplete combustion.


#21

S

Skippydiesel

The burn rate difference between 87 and 92 is negligible in stock small engines. We are not doing max HP pulls on a dyno.

Has anyone seen a small engine damaged from preignition?
No High octane fuels, will not cause "knocking" in small engines.
They will have little if any effect, good or bad however your expenditure will increase for no benefit.


#22

S

Skippydiesel

The issue isn't preignition; it's incomplete or partial combustion. High octane fuels are designed to combust at a much higher compression than small engines produce, on average around double.
In small engines there is no significant difference between the burn/ power developed, of a high or low octane fuel (subject to the low octane fuel not being below that recommended by the engine maker).
It would take sophisticated engine testing equipment, well outside most home/small business owners access, to see any difference at all.
Using fuel of an octane rating above that advised by the engine maker, will do no harm to the engine but will certainly lighten your pocket unnecessarily.
My comments are limited to petrol engines - diesel being a whole other subject.


#23

Tiger Small Engine

Tiger Small Engine

In small engines there is no significant difference between the burn/ power developed, of a high or low octane fuel (subject to the low octane fuel not being below that recommended by the engine maker).
It would take sophisticated engine testing equipment, well outside most home/small business owners access, to see any difference at all.
Using fuel of an octane rating above that advised by the engine maker, will do no harm to the engine but will certainly lighten your pocket unnecessarily.
My comments are limited to petrol engines - diesel being a whole other subject.
A local competitor small engine shop apparently puts VP fuel in equipment (that needs it) that he works on. Customer gave him a 3 star rating in review because he was charged $50 for about a half gallon of gas. Shop owner reply is that he uses this fuel so he can “guarantee” the repair/service. I guess the “warranty” runs out after a half gallon of high speed gas.

I am always putting fuel in customer equipment that are low or out. Amazingly it is 87 octane 10% ethanol gas, and have no problems or comebacks as a result.

Compression in a healthy 4-stroke engine should be 120 psi plus when tested. Common sense should tell people that 2-6 points of difference in octane rating for a small engine is negligible at best. We are talking about a relatively low compression engine (compared to vehicles) that runs at 3600 rpm. Not a NASCAR or top fuel dragster where it actually matters.


#24

Hammermechanicman

Hammermechanicman

You guys shouldn't be debunking long held beliefs. Next you are going to say things like it doesn't matter who has the best oil or oil filter. Or starting fluid doesn't blow up gas engines.

😱😱😱😱😱😱😱😱🤣


#25

7394

7394

(y)


#26

R

Rivets

I’m smarter than you. My theory’s are facts, your theory’s are just what you want to believe. Remember, everything you read on the World Wide Web is the absolute truth and based on time honored facts, so what ever you say won’t change my mind.


#27

stevestd

stevestd

The new Sheetz gas station near our house happens to sell ethanol free fuel, however the octane rating seems to be 90 (instead of the usual 87)
Is this higher octane safe for my Kohler VTwinand for my Honda self propelled mower?


#28

G

Gord Baker

The new Sheetz gas station near our house happens to sell ethanol free fuel, however the octane rating seems to be 90 (instead of the usual 87)
Is this higher octane safe for my Kohler VTwinand for my Honda self propelled mower?
Higher Octane Fuel simply burns slower so there is no knock on High (9.7 t0 12:1) Compression engines.
You are lucky to be able to buy Ethanol free fuel. Can't in Canada thanks to Lieberals.


#29

R

Rickcin

Higher Octane Fuel simply burns slower so there is no knock on High (9.7 t0 12:1) Compression engines.
You are lucky to be able to buy Ethanol free fuel. Can't in Canada thanks to Lieberals.
That is really pathetic, those people are ignorant ❗


#30

TonyPrin

TonyPrin

That is really pathetic, those people are ignorant ❗
Why?


#31

G

Gebo

Just make sure you are getting your non-ethanol gas from a dedicated non-ethanol pump. Otherwise, you will getting some ethanol in your gas. Assuming the last
person that pumped got ethanol gas.


#32

G

GrumpyCat

Just buy E10 from a high volume gas station. Only buy a month or two’s supply at a time. Don't store the can on cold concrete because cold fuel with warm moist air condenses moisture from the air no matter ethanol or not.

90 octane (sic) won’t hurt anything, won’t help. When engine is designed for 87 AKI then 87 is optimal. combustion pressures, flame rate, etc.


#33

TonyPrin

TonyPrin

Looks like consensus is that 90 (or may be higher) octane gas doesn't harm small engines despite my posts to the contrary. And that's OK. Several noted that the impact of 90 octane gas versus 87 octane is negligible at most so the benefit isn't worth the incremental cost. Beyond that, ethanol free fuel is less harmful to small engines than E10, but any potential harm can be mitigated by limiting storage to less than 2 months.


#34

G

GrumpyCat

The only harm ”from” ethanol is that it carries water in solution, then carries that water into the carburetor. If allowed to sit it will do nasty things. No additive or treatment does any good.

Small engines have ventilated gas tanks, open to the atmosphere, open to collecting moisture. Automobiles have sealed gas tanks with very little outside air axchange.


#35

S

SamB

I’m smarter than you. My theory’s are facts, your theory’s are just what you want to believe. Remember, everything you read on the World Wide Web is the absolute truth and based on time honored facts, so what ever you say won’t change my mind.
Seen on the internet...."He's a French Model"


#36

TonyPrin

TonyPrin

The only harm ”from” ethanol is that it carries water in solution, then carries that water into the carburetor. If allowed to sit it will do nasty things. No additive or treatment does any good.

Small engines have ventilated gas tanks, open to the atmosphere, open to collecting moisture. Automobiles have sealed gas tanks with very little outside air axchange.
My understanding is slightly different. Ethanol doesn't create water; it must enter the gas tank at time of purchase or through vents. Ethanol attracts water in the tank which readily attaches to the ethanol. Water in ethanol does inconsequential harm to the engine, no more than water in pure gasoline.

However, ethanol can only absorb a finite amount of water at any given temperature before it becomes oversaturated, causing phase separation. When phase separation occurs, the water separates from the ethanol. At 60F, ethanol can absorb .5% water or approx. 1 1/4 tablespoons of water per gallon prior to phase separation. It is this unattached water that causes damage.


#37

7394

7394

I test my 100% gas from my same gas station once once or twice a year. Just for my peace of mind.. It's extremely simple to test it.

Attachments





#38

S

Skippydiesel

Just buy E10 from a high volume gas station. Only buy a month or two’s supply at a time. Don't store the can on cold concrete because cold fuel with warm moist air condenses moisture from the air no matter ethanol or not.

90 octane (sic) won’t hurt anything, won’t help. When engine is designed for 87 AKI then 87 is optimal. combustion pressures, flame rate, etc.
I have never used ethanol blended fuel, so some of my commentary is speculative.
  • Agree with purchasing any fuel from a high volume/turn over supplier.
  • Also only purchasing sufficient fuel for your relativly short term needs (whatever they may be)
Storage of petrol:

Most, if not all, petrol will store for at least 6 months plus, with negligible deterioration. To achieve this, the container must be gas/air tight and filled to 75% capacity or more. If these two factors are met, then the storage temperature has little bearing on its keeping quality.

As has been pointed out by others - Most fuel tanks are open to atmosphere:
  • This means that air can enter/exit. Air contains moisture (% will vary according to prevailing condition). Warm air contains more moisture than cold. When warm moist air enters the tank, the moisture will condense, on cold inner walls of the tank, forming free water (droplets), . These droplets will fall to & collect at the bottom of the tank. Petrol with ethanol may absorb some of this water - this is okay as it will have little effect on the combustion process. However the free water at the bottom of the tank may may # rust the tank bottom or # enter the fuel delivery/metering system and cause engine running issues. The solution is to regularly drain the tank sump (if fitted) any water traps and the carburettor float bowl thus removing free water.
  • Also means any tendency of the fuel (petrol) to loose volatile components, causing a reduction in fuel quality. Filling the tank (minimising air space) will slow the process, as will mixing in fuel "inhibitors" however for long term storage it may be best to empty the whole fuel system. NOTE: In most short term storage situations, adding fresh fuel to old, will restore most of the fuels performance.


#39

T

TobyU

The reason for my question was because when reading up on using a higher octane in small engines, one article said it can cause small engines to run hotter and possibly cause damage to the valves.
They are wrong.
I would venture to say that even an extreme cases they are still wrong!
There's a lot of crap on the internet and a lot of people that think things are true and then they say it and other people believe them.
I'm not going to claim this next statement is absolute fact but I think you take some 108 to 110 octane racing fuel and put it in your lawn mower and it wouldn't get your egts or valves a bit hotter to worry about.
Do you need this much in a lawn mower with approximately 7 to 1 compression ratio?
You certainly do not.
These things are "Low performance little turds". #tm.
That's my little trademark seal because I'm claiming that expression has my own but you're free to use it just know that I invented it.

I tell at least three or four customers weekly that these lawn mower engines are low performance little turds.
They are still far better than anything battery powered though!!

Low performance makes them more forgiving and if they were high performance finally tuned machines squeezing out every last drop of power per cubic inch or do I have to say CC now?

Back to octane, putting 87 versus 91 or 93 in an engine will make no difference and will in no way harm a small lawn mower engine.
Personally, I'm not a fan paying 50 or 60 cents more or sometimes almost a dollar for ethanol free fuel or higher octane.
We've already established you don't need the higher octane and all fuel will still mess up if it sits long enough and I have had things sit over 3 years with simply 1 oz of sta-bil in each gallon of fuel and start right up in about three pulls.
This makes it pointless and a waste of money to buy ethanol free fuel.

Just make sure you never buy their 88 stuff because that has at least 15% ethanol and even the gas cap on the newer mowers tells you never to use that.


#40

T

TobyU

All of the premium small 2 stroke manufacturers, aka Stihl Husqvarna, Makita/Dolmar require a minimum of 90+ in their products to prevent pre-ignition which will cause engine damage. But premium fuel doesn't burn any hotter than non-premium fuel because it has the same btu rating. The only disadvantage is the higher cost to operate because in most cases will not change your fuel usage.

And my personal opinion is premium stores better, but that may just be my opinion and could be incorrect.
I haven't found any of the premium fuels to store any better than the standard 87.
I think most feelings that it is is just confirmational bias or some type of bias or wishful thinking.
While some of those fuels, especially shell v power are probably excellent at keeping things clean when they're actually running and preventing detonation and a few other things, none of these companies are refining gas to sit for six or eight months and not congeal or to leave fewer deposits and crud once they do evaporate.


#41

T

TobyU

I have never used ethanol blended fuel, so some of my commentary is speculative.
  • Agree with purchasing any fuel from a high volume/turn over supplier.
  • Also only purchasing sufficient fuel for your relativly short term needs (whatever they may be)
Storage of petrol:

Most, if not all, petrol will store for at least 6 months plus, with negligible deterioration. To achieve this, the container must be gas/air tight and filled to 75% capacity or more. If these two factors are met, then the storage temperature has little bearing on its keeping quality.

As has been pointed out by others - Most fuel tanks are open to atmosphere:
  • This means that air can enter/exit. Air contains moisture (% will vary according to prevailing condition). Warm air contains more moisture than cold. When warm moist air enters the tank, the moisture will condense, on cold inner walls of the tank, forming free water (droplets), . These droplets will fall to & collect at the bottom of the tank. Petrol with ethanol may absorb some of this water - this is okay as it will have little effect on the combustion process. However the free water at the bottom of the tank may may # rust the tank bottom or # enter the fuel delivery/metering system and cause engine running issues. The solution is to regularly drain the tank sump (if fitted) any water traps and the carburettor float bowl thus removing free water.
  • Also means any tendency of the fuel (petrol) to loose volatile components, causing a reduction in fuel quality. Filling the tank (minimising air space) will slow the process, as will mixing in fuel "inhibitors" however for long term storage it may be best to empty the whole fuel system. NOTE: In most short term storage situations, adding fresh fuel to old, will restore most of the fuels performance.
You hit the nail on the head when you talked about long-term storage and the fact that most people don't have these best conditions.
We all hate these newer and the vast variety of these EPA nozzles but the only thing they do better is they keep the can airtight and keep the gas fresher longer.
It doesn't make things perfect or all warm and fuzzy but it certainly helps.

Most people have a gas can that the top is pretty much wide open and they pay no attention to when they get gas and when that gas can is getting down to the last couple of inches, especially in a 5 gallon can, and they're going out to mulch leaves for the last time of the year....they just pour that old stale stuff right into their mower and sometimes they tip it all the way up and get all the grass particles and dirt and everything else and even water that's been sitting at the bottom from that gas can right into their lawn mower tank.
They mow because it runs just fine that day...but come back in a week and especially come back the next March or April and that mower doesn't stand a chance of running.


#42

Hammermechanicman

Hammermechanicman

Just my personal experience.
I have kept 87 E10 gas in sealed gas cans for over a year with no problem.
The 1989 motor home with 454 carb engine sat for 5 years in the barn and started and ran fine. E10 87 gas with no stabilizer or other fuel treatment. Now gets used once a year to take the grandkids camping. Starts fine.
I use regular 87 E10 in about 20 pieces of equipment without issue. I have 7 5 gallon gas cans I fill a few times a year for equipment. As long as I keep then SEALED I have no issues. I fill them in the fall for the generator and if no power failures use the gas in the spring. Never have a problem.


#43

7394

7394

(y)


#44

S

Skippydiesel

Just my personal experience.
I have kept 87 E10 gas in sealed gas cans for over a year with no problem.
The 1989 motor home with 454 carb engine sat for 5 years in the barn and started and ran fine. E10 87 gas with no stabilizer or other fuel treatment. Now gets used once a year to take the grandkids camping. Starts fine.
I use regular 87 E10 in about 20 pieces of equipment without issue. I have 7 5 gallon gas cans I fill a few times a year for equipment. As long as I keep then SEALED I have no issues. I fill them in the fall for the generator and if no power failures use the gas in the spring. Never have a problem.
That's great my friend, however I would suggest that you drain the tank sump and any in line water traps, at least once per year.


#45

B

bertsmobile1

So I guess my original post had some validity but my concern still is as follows;
If the available ethanol free fuel is 91 octane, is it safe to use that or should I mix a little normal fuel (10% ethanol) to dilute the octane rating?

Another point of interest is that since most service stations have 4 different grades of gas with a common hose and nozzle, whenever we make a selection to pump gas, we are going to first receive the fuel that’s in the hose from the last user. The valve to that controls the flow is in the pump, not all the way back to the tank.

I realize it’s only a small amount of fuel, however if you were filling a 1 or 2.5 gallon container, it would be a significant percentage.
One way around this would be to first pump of your fuel of choice into your vehicle so that you get 100 percent of your desired fuel for your mowers or small engines.
High octane is necessary in high compression engines
Mower engines are pretty low compression & low reving as well
They would be happy running power kerosene once the manifold got hot enough to vapourise the kerro.
There is a massive amount of ignorant B S spread by the ignorant &/or illinformed who read some thing that applies to NASCAR engines or formula 1 open wheeler engines then blindly apply it to mower engines because they do not understand the difference between an engine that runs 12:1 compression @ 12,000 rpm to one that runs 8:1 compression at 3,600 rpm.


#46

B

bertsmobile1

The only harm ”from” ethanol is that it carries water in solution, then carries that water into the carburetor. If allowed to sit it will do nasty things. No additive or treatment does any good.

Small engines have ventilated gas tanks, open to the atmosphere, open to collecting moisture. Automobiles have sealed gas tanks with very little outside air axchange.
Err if no air gets in how does the fuel get out ?
All tanks are vented some where


#47

T

Timbuktu

As far as ethanol, I was always under the impression that it was not good for small engines. If so, maybe this is outdated information. I personally don't use ethanol in anything I own, small motors or vehicles.


#48

T

TobyU

High octane is necessary in high compression engines
Mower engines are pretty low compression & low reving as well
They would be happy running power kerosene once the manifold got hot enough to vapourise the kerro.
There is a massive amount of ignorant B S spread by the ignorant &/or illinformed who read some thing that applies to NASCAR engines or formula 1 open wheeler engines then blindly apply it to mower engines because they do not understand the difference between an engine that runs 12:1 compression @ 12,000 rpm to one that runs 8:1 compression at 3,600 rpm.
Yep.
More like barely over 7 to 1 compression ratio and 2900 RPMs for most things today. Lol
You are so right though. People read something on the Internet and if it's conveyed to them in just a certain way they accept it as the gospel truth. SMH

There's also a lot of information over the past few years that has kind of been changed and rewritten which makes things even worse.
It's not that they're actually lying but they're not giving a complete picture of everything or even the options one is likely to encounter.
They, certain people, groups, companies etc are literally trying to shape the world by what information they promote.
Unfortunately they are doing this to a pretty good point.


#49

T

TobyU

As far as ethanol, I was always under the impression that it was not good for small engines. If so, maybe this is outdated information. I personally don't use ethanol in anything I own, small motors or vehicles.
It's just not that big of a deal.
I don't think I have used any gas that was ethanol free since 1998 or so.
Everything in my area has been 10% ethanol since then.
Prior to that even Meijer department store gas station had three grades and two of the three were ethanol free from what I remember.
Back in the day it was Speedway that came on strong and all of their fuel had 10% ethanol. They also used to be cheaper than everyone else and we used to say all the time "I'm not buying that cheap crap gas!" because for only 3 or 4 cents more at other stations we could get ethanol free.
But that all changed in just a few short years.


#50

TonyPrin

TonyPrin

High octane is necessary in high compression engines
Mower engines are pretty low compression & low reving as well
They would be happy running power kerosene once the manifold got hot enough to vapourise the kerro.
There is a massive amount of ignorant B S spread by the ignorant &/or illinformed who read some thing that applies to NASCAR engines or formula 1 open wheeler engines then blindly apply it to mower engines because they do not understand the difference between an engine that runs 12:1 compression @ 12,000 rpm to one that runs 8:1 compression at 3,600 rpm.
Here's the reality of all this in a nutshell:
  • The consensus is there is no meaningful detriment (if any) in using high octane fuel in small engines. (Not my opinion but most aren't with me.)
  • No one is suggesting a high octane benefit in small engines. There is a price detriment to high octane which makes it less desirable unless a trade-ff exists.
  • E10 gasoline has a potential issue from phase separation, mitigated by prudent and short-term storage practices. Many don't see it as a meaningful concern.


#51

T

TobyU

Here's the reality of all this in a nutshell:
  • The consensus is there is no meaningful detriment (if any) in using high octane fuel in small engines. (Not my opinion but most aren't with me.)
  • No one is suggesting a high octane benefit in small engines. There is a price detriment to high octane which makes it less desirable unless a trade-ff exists.
  • E10 gasoline has a potential issue from phase separation, mitigated by prudent and short-term storage practices. Many don't see it as a meaningful concern.
The facts are that all things being equal, you will have more fuel related problems with e10 ethanol fuel anywhere with pure fuel but - all things aren't equal for everyone and with all people. Lol
I have found that using one ounce of fuel stabilizer with every gallon of fuel makes the e10 ethanol work just as well and last just as long as any "pure" gas you may get.

As with everything, your mileage may vary. 😂


#52

Hammermechanicman

Hammermechanicman

The one place i have found where E10 is a problem is with old equipment with steel gas tanks. I work on a lot of old stuff. Before ethanol pure gas didn't attract water and rust out tanks. Ethanol gas has ruined many steel tanks. I use Red Kote to line the tanks to try and save them. The old 5hp Briggs lasted forever till ethanol gas and it destroys the tanks.


#53

A

Air4Dave

And everything you just posted has been proven false. Some of it may of been considered true years ago, but with current fuel formulation is all false. Higher octane reduced pre-ignition but has the same burn rate and btu output as 87 octane.
I concur! Being a former Chevron employee of 27 years, and understanding how and why the different octanes levels are obtained, and for what reasons, I can say that using the premium fuels of 90+ octanes, without ethanol, is a great way to keep your small engines clean burning and hydrocarbon free! I have been using 92, or 91 ethanol free fuels for several years now and have NEVER had any issues of using this octane level. Doesn't matter if you have a 2-cycle or 4 cycle, older equipment or newer, it will work just fine.


#54

S

Skippydiesel

The one place i have found where E10 is a problem is with old equipment with steel gas tanks. I work on a lot of old stuff. Before ethanol pure gas didn't attract water and rust out tanks. Ethanol gas has ruined many steel tanks. I use Red Kote to line the tanks to try and save them. The old 5hp Briggs lasted forever till ethanol gas and it destroys the tanks.

I do not agree, that ethanol destroys steel tanks - what destroys steel tanks is water that is allowed to collect at the bottom of the tank that the operator/owner of the equipment fails to remove on a regular basis.
Ethanol blends may attract more water than straight petrol however condensation occurs, whatever the fuel type.


#55

Hammermechanicman

Hammermechanicman

I do not agree, that ethanol destroys steel tanks - what destroys steel tanks is water that is allowed to collect at the bottom of the tank that the operator/owner of the equipment fails to remove on a regular basis.
Ethanol blends may attract more water than straight petrol however condensation occurs, whatever the fuel type.
That's what I mean the ethanol absorbs water and when left in the tank for a long time it rusts the tanks.


#56

ILENGINE

ILENGINE

I do not agree, that ethanol destroys steel tanks - what destroys steel tanks is water that is allowed to collect at the bottom of the tank that the operator/owner of the equipment fails to remove on a regular basis.
Ethanol blends may attract more water than straight petrol however condensation occurs, whatever the fuel type.
Water in fuel tanks and tanks rusting out was happening in the 70's prior to widespread use of ethanol in fuel. People would add Heat to their fuel tanks in the winter because the water was freezing and preventing fuel flow to the carb on their auto's


#57

TonyPrin

TonyPrin

The one place i have found where E10 is a problem is with old equipment with steel gas tanks. I work on a lot of old stuff. Before ethanol pure gas didn't attract water and rust out tanks. Ethanol gas has ruined many steel tanks. I use Red Kote to line the tanks to try and save them. The old 5hp Briggs lasted forever till ethanol gas and it destroys the tanks.
That's what I mean the ethanol absorbs water and when left in the tank for a long time it rusts the tanks.

Spoiler alert: water has been rusting metal parts on machinery since the industrial revolution. Sorry, but water causes rust (i.e., corrosion), not ethanol. And ethanol doesn't create water. The water in the form of liquid or condensation must already be there. Ethanol is hydrophilic, meaning it holds water not that it creates water or attracts it. Since it's already in the gas tank, the tank would rust without the ethanol. I've seen many rusted mower decks. Perhaps that's caused by ethanol, too.


#58

B

bertsmobile1

Spoiler alert: water has been rusting metal parts on machinery since the industrial revolution. Sorry, but water causes rust (i.e., corrosion), not ethanol. And ethanol doesn't create water. The water in the form of liquid or condensation must already be there. Ethanol is hydrophilic, meaning it holds water not that it creates water or attracts it. Since it's already in the gas tank, the tank would rust without the ethanol. I've seen many rusted mower decks. Perhaps that's caused by ethanol, too.
Sorry Tony but fuel tanks rusting only became a big problem when some idiot 1/2 wit convinced government ministers who know nothing about chemistry & metallurgy to stop the use or Tern Plate for fuel tanks.
For those who do not know Tern Plate is like tin plate but the coating is 99.99% pure lead
This is why the tanks from old cars are usually a funny grey colour inside and can sit outside in the weather for decades without rusting .


#59

TonyPrin

TonyPrin

Sorry Tony but fuel tanks rusting only became a big problem when some idiot 1/2 wit convinced government ministers who know nothing about chemistry & metallurgy to stop the use or Tern Plate for fuel tanks.
For those who do not know Tern Plate is like tin plate but the coating is 99.99% pure lead
This is why the tanks from old cars are usually a funny grey colour inside and can sit outside in the weather for decades without rusting .
bertsmobile1, thanks for confirming that fuel tank corrosion today has nothing to do with E10. Note, however, that the move from terne plated fuel tanks is not directly related to legislation and regulation. Rather many car companies moved away from terne (in non-diesel steel gas tanks in general) and to plastic for cost and weight reasons. BTW, I believe there's a move toward plastic or fiberglass in fuel storage tanks, as well.


#60

G

GrumpyCat

Err if no air gets in how does the fuel get out ?
All tanks are vented some where
Air gets in automotive fuel systems, it just doesn't flow in and out getting replenished with fresh moisture.

And then there is the 2004-2009 Prius whose fuel tank consisted of a bladder/bellows in a plastic case. Very little air volume over the fuel. As fuel was consumed the bladder collapsed.


#61

G

GrumpyCat

As far as ethanol, I was always under the impression that it was not good for small engines. If so, maybe this is outdated information. I personally don't use ethanol in anything I own, small motors or vehicles.
Ethanol is not good. But isn't The End Of The World.

The problem with small engines is the simple fuel system exposed to moist air. The problem is in how small engines are often left out in the weather.

Ethanol-free gasoline still accumulates water, but the water doesn't mix. The water can be decanted off the bottom of the tank and the gasoline still good to use.


#62

G

GrumpyCat

The one place i have found where E10 is a problem is with old equipment with steel gas tanks. I work on a lot of old stuff. Before ethanol pure gas didn't attract water and rust out tanks. Ethanol gas has ruined many steel tanks. I use Red Kote to line the tanks to try and save them. The old 5hp Briggs lasted forever till ethanol gas and it destroys the tanks.
Ethanol is not "destroying tanks".

In 1984 I had to buy a new gas tank for my Honda motorcycle because it somehow had over 3/4" of water accumulated in my attached garage over the winter. Formed a nice line of holes through the tank at the gasoline/water line.


#63

G

GrumpyCat

I do not agree, that ethanol destroys steel tanks - what destroys steel tanks is water that is allowed to collect at the bottom of the tank that the operator/owner of the equipment fails to remove on a regular basis.
Ethanol blends may attract more water than straight petrol however condensation occurs, whatever the fuel type.
And ethanol allows the water to carry in the fuel, exposing the entire tank not just the bottom. This is the problem with ethanol + water in carburetors. With pure gasoline a drop of water in the carburetor kills the engine. In ethanol, it simply leans the mixture, but probably goes right through the carburetor and engine.


#64

TonyPrin

TonyPrin

Err if no air gets in how does the fuel get out ?
All tanks are vented some where
Keep in mind that gasoline is a liquid and air is made up of gases. The gases expand and compress to fill the void as the liquid volume increases or decreases without impact unless the gas is pressurized which, in this case, it is not. There is no one-to-one exchange.


#65

G

GrumpyCat

Water in fuel tanks and tanks rusting out was happening in the 70's prior to widespread use of ethanol in fuel. People would add Heat to their fuel tanks in the winter because the water was freezing and preventing fuel flow to the carb on their auto's
The product is called Heet, and it is primarily ethanol.

So ironically today people are complaining about that which they used to buy and deliberately add. Because it was better to suspend water in gasoline to get it out and through the system than have it puddle, freeze, and block fuel passages.


#66

ILENGINE

ILENGINE

The product is called Heet, and it is primarily ethanol.

So ironically today people are complaining about that which they used to buy and deliberately add. Because it was better to suspend water in gasoline to get it out and through the system than have it puddle, freeze, and block fuel passages.
Actually Heet is Methanol Or Wood alcohol with other additives.


#67

TonyPrin

TonyPrin

And ethanol allows the water to carry in the fuel, exposing the entire tank not just the bottom.
There are at least two reasons this is incorrect. First, ethanol dispersing water throughout the tank is a good thing. When spread throughout the entire tank only a small portion of the water comes in contact with the sides. Consider the perimeter of a 12" square is 48" while the area is 144". In this case 67% of the water is in suspension away from the sides. Beyond that, ethanol only holds up to .5 water, while water at the bottom of a tank is 100% water.

With pure gasoline a drop of water in the carburetor kills the engine. In ethanol, it simply leans the mixture, but probably goes right through the carburetor and engine.
Clearly phase separation (when ethanol releases water due to saturation) can cause engine and carburetor problems. Is there any proof water in ethanol is more damaging than pure water as you imply?


#68

G

grpascott

The new Sheetz gas station near our house happens to sell ethanol free fuel, however the octane rating seems to be 90 (instead of the usual 87)
Is this higher octane safe for my Kohler VTwinand for my Honda self propelled mower?
I have been using 93 octane non ethanol in my bad boy (kohler 27hp twin) and all my small engines for three years. Carb problems went away, even in winter slow season. Fuel is cheaper than a new engine. Don't neglect routine maint like air filters, fuel filters and regular oil/filter changes. Also, in spring remove air shroud and check for clogged cooling fins. Happy mowing!


#69

G

grpascott

A note of clarification, on my Kohler I run an offset key on the flywheel, giving me about 32 degrees of total advanced ignition. So the 93 octane is a benefit and I can mow at 2500 to 2800 rpm without my engine bogging and it runs cooler and more economical. Keep blades sharp!


#70

G

GrumpyCat

There are at least two reasons this is incorrect. First, ethanol dispersing water throughout the tank is a good thing. When spread throughout the entire tank only a small portion of the water comes in contact with the sides. Consider the perimeter of a 12" square is 48" while the area is 144". In this case 67% of the water is in suspension away from the sides. Beyond that, ethanol only holds up to .5 water, while water at the bottom of a tank is 100% water.
Water is in contact. Water plus oxygen makes rust.

Clearly phase separation (when ethanol releases water due to saturation) can cause engine and carburetor problems. Is there any proof water in ethanol is more damaging than pure water as you imply?
Clearly you have never disassembled a carburetor or fuel injector which which sat unused with water in ethanol gasoline.

Ethanol gasoline phase separation is the ethanol + water falling out of solution. If only water fell out no one would care, but the mix is nasty.


#71

TonyPrin

TonyPrin

Water is in contact. Water plus oxygen makes rust.
Agreed. But water in ethanol suspension is dispersed throughout the tank (mostly away from the tank wall) while water not in suspension is concentrated at the bottom wall of the tank.

Clearly you have never disassembled a carburetor or fuel injector which which sat unused with water in ethanol gasoline.

Ethanol gasoline phase separation is the ethanol + water falling out of solution. If only water fell out no one would care, but the mix is nasty.
Through the years I've worked on many carburetors but never compared them. I've seen extensive slime and residue in them for years, long before E10 existed. Gasoline with or without ethanol shouldn't be kept in the carburetor long term.

That's not to say phase separation isn't an issue and I agree phase separation must be avoided.

Finally, it's not debated that water in a gas tank will cause rust. But first you say, "water is in contact. Water plus oxygen makes rust". Three sentences later you say, "if only water fell out no one would care". It can't be both.


#72

S

sessman55

The new Sheetz gas station near our house happens to sell ethanol free fuel, however the octane rating seems to be 90 (instead of the usual 87)
Is this higher octane safe for my Kohler VTwinand for my Honda self propelled mower?
.the higher octane rating will not adversely affect your engine.


#73

T

TobyU

Actually Heet is Methanol Or Wood alcohol with other additives.
Yes. iso-heet is the isopropyl one.


#74

T

TobyU

I have been using 93 octane non ethanol in my bad boy (kohler 27hp twin) and all my small engines for three years. Carb problems went away, even in winter slow season. Fuel is cheaper than a new engine. Don't neglect routine maint like air filters, fuel filters and regular oil/filter changes. Also, in spring remove air shroud and check for clogged cooling fins. Happy mowing!
Well, first of all carb problems or fuel related issues are never going to cause you to need a new engine! They are simply aggravating.
Secondly, I haven't used 1 oz of fuel that didn't have 10% ethanol in it for probably the past 22 years.
This is not because I wanted to but because all the stations went to that so I didn't have a convenient choice and now that I do I'm not going to pay a dollar to a dollar and 10 cents more for ethanol free.
I simply started using sta-bil, the plain old original version at 1 oz for every gallon of fuel which used to be the long-term storage recommendation for up to 2 years and I have had no carburetor or fuel issues since then.


#75

T

TobyU

A note of clarification, on my Kohler I run an offset key on the flywheel, giving me about 32 degrees of total advanced ignition. So the 93 octane is a benefit and I can mow at 2500 to 2800 rpm without my engine bogging and it runs cooler and more economical. Keep blades sharp!
Keep telling yourself that but trust me it's not the case on most engines and probably not yours either.
Have you really used a degree wheel or a timing light with a degree dial to check your total advance?

Sure, a lot of us did this on our old hot rods and muscle cars but these engines are not that! Lol
They are low performance little turds with maybe 7.2 to 1 compression ratio on a good day. Lol
They are beyond laughable that a 597 CC twin engine in 2024 puts out 22 maybe 24 horsepower when a 550 cc Japanese sport bike engine in 1987 put out 84 horsepower and for over 20 something years they've been putting out well over 100.
I will repeat, lawn mower engines are low performance little turds!
If you want to get more performance and non-bogging out of your engine, you would likely do better with carburetor or intake modification and or valve adjustment since most of these where extremely to the loose side and you're losing a little bit of valuable lift.
Maybe even exhaust modification.
Now I'm not going to say that timing has nothing to do with it but I find it far easier to adjust the RPMs and the governor spring especially if it has multiple holes in the arm to give it faster adjustment ability and it hits a harder load then to remove shrouds and fly wheels and do offset keys etc.
But to each their own.


#76

T

TobyU

Agreed. But water in ethanol suspension is dispersed throughout the tank (mostly away from the tank wall) while water not in suspension is concentrated at the bottom wall of the tank.


Through the years I've worked on many carburetors but never compared them. I've seen extensive slime and residue in them for years, long before E10 existed. Gasoline with or without ethanol shouldn't be kept in the carburetor long term.

That's not to say phase separation isn't an issue and I agree phase separation must be avoided.

Finally, it's not debated that water in a gas tank will cause rust. But first you say, "water is in contact. Water plus oxygen makes rust". Three sentences later you say, "if only water fell out no one would care". It can't be both.
I too was having to clean out the carburetor bowl on Tecumseh engines back in the seventies and early '80s way before any of the fuel had 10% ethanol in it.
You would typically find a big what I call grease bubble floating around but more than likely a water and moisture bubble.
Once you dumped the bowl and let some fresh gas run through, it was good to go.


#77

G

GearHead36

They are beyond laughable that a 597 CC twin engine in 2024 puts out 22 maybe 24 horsepower when a 550 cc Japanese sport bike engine in 1987 put out 84 horsepower and for over 20 something years they've been putting out well over 100.
I will repeat, lawn mower engines are low performance little turds!
I disagree. I used to be "into motorcycles". Yes, they generate a LOT of power for their displacement, but they do it at 10000+ RPM's. OPE engines are typically rated at 3600 RPM. RPMs make all the difference. See what the sportbike engines produce at 3600. Also OPE engines are designed to survive much of the abuse and neglect they tend to experience. Yes they have low compression ratios, but they will also survive lots of abuse. I bought a ZTR with a Kohler Confidant engine. I used it for a half season. In the off season, I found that the cylinder cooling fins were almost completely blocked, and it still survived. Most of it's cooling capacity had been disabled, and it still survived. Remove the cooling from a motorcycle engine, and see how long it lasts.

Not to denigrate motorcycle engines. If you want that kind of performance, you best keep up with the maintenance. They often get abused, too, but in a different way. They're remarkable examples of engineering. But OPE engines are good too. Just a different set of design criteria.


#78

7394

7394

(y)


#79

T

TobyU

I disagree. I used to be "into motorcycles". Yes, they generate a LOT of power for their displacement, but they do it at 10000+ RPM's. OPE engines are typically rated at 3600 RPM. RPMs make all the difference. See what the sportbike engines produce at 3600. Also OPE engines are designed to survive much of the abuse and neglect they tend to experience. Yes they have low compression ratios, but they will also survive lots of abuse. I bought a ZTR with a Kohler Confidant engine. I used it for a half season. In the off season, I found that the cylinder cooling fins were almost completely blocked, and it still survived. Most of it's cooling capacity had been disabled, and it still survived. Remove the cooling from a motorcycle engine, and see how long it lasts.

Not to denigrate motorcycle engines. If you want that kind of performance, you best keep up with the maintenance. They often get abused, too, but in a different way. They're remarkable examples of engineering. But OPE engines are good too. Just a different set of design criteria.
I'm not sure which part of my statement you're disagreeing with but it's still quite factual.
Now, my comment that they are low performance little turds has some opinionated flair to it but they are in fact low performance compared to most any of those motorcycle engines were talking about.
Sure, there are lots of other differences but they are certainly low performance compared to them.

You are comparing RPMs in connection to horsepower but then again, this further confirms and supports that they are low performance little turds because they aren't capable of doing 8,500 to 12,000 RPMs and sustaining it like the motorcycle engines are and even if they did I doubt you would see anywhere above 60% of the power the motorcycles produce.

So I'm not sure which part you're taking issue with but tons of what I said is factual.

The one thing that I also always say about these engines that I did not put in my first post is while they are low performance little turds, they are also VERY FORGIVING. Lol
They put up with decades of abuse and neglect and keep on doing their job quite well.
But often seems to be the case that high quality, precision equipment can be more delicate and need more maintenance and care given to it in operation whereas crude old rudimentary basic stuff is tolerant of about everything.

So I really love these small air cooled engines, in fact I like them far more than motorcycle engines and I think they are the right tool for the job which is always important.
I'm simply not impressed by the horsepower but they shouldn't be trying to impress me or anyone for that matter.
The entire horsepower game is a joke because no one needs 20 horsepower to cut their grass with a 42-in rider!
In fact, people were doing it for decades with 12 and 14 horsepower engines and even those were probably slightly inflated with their specs but not nearly to the degree they were later.

I also don't need to be impressed with the latest and greatest and auto chokes and fuel injection etc.
I don't want more things to go wrong or more things for more people to have to learn or get adjusted to.

Let's just stay the course and get all the bugs worked out and by this point in time they should have been able to make a lawnmower engine that's darn near bulletproof that lasts the minimum 20 years but of course that would be counterproductive for them.

I want simplicity, durability and longevity and many of these engines over the decades have given all three.


#80

G

GearHead36

I'm not sure which part of my statement you're disagreeing with but it's still quite factual.
This part:
I will repeat, lawn mower engines are low performance little turds!
If your evaluation of an engine's "turdness" is equated solely to HP, then, yes, OPE engines are turds. They don't put out NEAR the HP per liter of motorcycle engines. I evaluate engines on their suitability for the task. In that sense, OPE engines are just fine for the job they do. Maybe even great. Most of them last a long time with very little attention*. I'm often amazed when I see an engine that is several years old, has had zero oil changes (or any other maintenance), and still runs fine once you do some maintenance on it.

* We won't talk about Inteks or Courages. 😂

The one thing that I also always say about these engines that I did not put in my first post is while they are low performance little turds, they are also VERY FORGIVING. Lol
They put up with decades of abuse and neglect and keep on doing their job quite well.
But often seems to be the case that high quality, precision equipment can be more delicate and need more maintenance and care given to it in operation whereas crude old rudimentary basic stuff is tolerant of about everything.
So you actually agree with me. You just get hung up over the power output. That very forgiving nature is a design criteria, which dictates operating at low levels of stress on the engine.

The entire horsepower game is a joke because no one needs 20 horsepower to cut their grass with a 42-in rider!
My current ZTR has a 27HP engine and 54" deck. Is it overpowered? I don't think so. If the grass is thick and tall because it hasn't dried out in a week, and it's a week overdue for mowing, that 27HP (or whatever it is) seems to be just enough to power through without significant bogging. I still have to slow down, but only a little. My previous ZTR had 17HP and a 48" deck, and it was definitely underpowered. In that same tall grass, I would have to slow almost to a crawl to keep it from choking. Does my current ZTR have 27HP? I don't know. Did my old one have 17HP? Don't know that either, and I don't care. The newer one gives a good cut without me having to slow way down, and that's what I care about. Maybe nobody needs 20HP for a 42" rider, and maybe that "20HP engine" doesn't really have 20HP, but I DO think mowers today have more power than they did before, and I have no problem with that. If you typically only use half of that power, the engine will last longer.


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