Ethanol-free, or 89 Octane

akbryant

Forum Newbie
Joined
Jun 10, 2017
Threads
4
Messages
9
I have an Echo string trimmer that owner's manual recommends 89 octane gas as it cleans engine better
I would prefer to use ethanol-free in it as it does so well in my 2 mowers. Any thoughts on this?
 

MParr

Lawn Addict
Joined
Jul 2, 2021
Threads
7
Messages
1,687
The 89 octane would be a minimum requirement.
Can you get 89 octane pure gas? If so, mix your own.
If you use small quantities, buy the canned stuff.
 

dougand3

Well-Known Member
Joined
Mar 10, 2012
Threads
12
Messages
448
What country are you? The manual for what country? USA 87 octane (R+M/2) would be 90.5 Octane (RON) in Europe.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
78
Messages
5,081
owner's manual recommends 89 octane gas as it cleans engine better
Octane has ZERO to do with engine cleaning. Let that percolate.

The higher the octane "number" is, the SLOWER the fuel burns. Why use higher octane fuel? High compression engines need slower burning fuel to resist knocking. Talking say 10:1 engines and higher compression.

Lower octane burns faster and has more explosive power per volume. Get E-0 87 octane and never look back.

I would prefer to use ethanol-free in it as it does so well in my 2 mowers. Any thoughts on this?
E-0 is the best. End of message.

E-0 has more explosive energy than any alcohol added fuel can offer. Even E-85. It takes a ton of alcohol or fuel volume to obtain a proper air/fuel ratio. Alky is cleaner burning and loves to make WATER in your fuel.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
78
Messages
5,081
What you need to be talking about is if you have an old gas can, wide open spout type, get rid of it. Water and trash love to pollute you can. Which passes to your mower carb, wondering why we have so many fuel related posts on here.

New style cans keep fuel fresher/cleaner.
 

ILENGINE

Lawn Royalty
Joined
May 6, 2010
Threads
43
Messages
10,730
Octane has ZERO to do with engine cleaning. Let that percolate.

The higher the octane "number" is, the SLOWER the fuel burns. Why use higher octane fuel? High compression engines need slower burning fuel to resist knocking. Talking say 10:1 engines and higher compression.

Lower octane burns faster and has more explosive power per volume. Get E-0 87 octane and never look back.
Something to keep in mind is there are a lot of weedeaters, chainsaws, trimmers in the 10:1 ratio. Several of the Kohler engines have a minimum compression of 160 psi, so they are pushing a 11-12:1 ratio.

What got me started down the high octane road is my 96 Dakota that spend half of it first 30 days of ownership in the shop over spark knock. That truck would sound like the rods were coming loose going up hill or taking off from a stop sign. Even though is recommended 87 octane, that truck never rattled again after going to high octane fuel. My current truck recommends minimum 89 octane with the 9.5: engine.
 

Tiger Small Engine

Lawn Addict
Joined
Dec 7, 2022
Threads
2
Messages
1,103
I have an Echo string trimmer that owner's manual recommends 89 octane gas as it cleans engine better
I would prefer to use ethanol-free in it as it does so well in my 2 mowers. Any thoughts on this?
I know I will get push back on this one. I have used 87 ethanol gas for 20 years and have seen no problems or issues and no power and performance difference. Also not a fan of fuel stabilizer, or True Fuel pre-mix in the gallon can. Keep your gas in a good secured container, keep it fresh and moving, and it will be fine. If in doubt, dump it out.
 

tank1949

Member
Joined
Oct 19, 2021
Threads
2
Messages
12
I know I will get push back on this one. I have used 87 ethanol gas for 20 years and have seen no problems or issues and no power and performance difference. Also not a fan of fuel stabilizer, or True Fuel pre-mix in the gallon can. Keep your gas in a good secured container, keep it fresh and moving, and it will be fine. If in doubt, dump it out.
Me too except gas would cause primer bulb and fuel lines to disintegrate. I use highest octane w/o ethanol that I can find.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
78
Messages
5,081
Use to drain everything over the winter. Lines obviously will dry up in that few months, crack and leak. Started using stabilizer year round. Stopped having to replace fuel lines in 5 mowers, back pack blower and trimmer. Oh and the hedge trimmers too. Never have to recall how old is this gas in the can. Only costs a few bucks. Yup on the primer bulbs drying up. Now I leave fuel in all year round. Keeps the lines lubed up and soft. Works for me. Do what works for you.
 
Top