10W-30 0r straight 30W? Why not 10W-40?

[twall]

Briggs and Stratton has approved the use of 5w30 synthetic oil in all of there engines. Winter or Summer for all temperature ranges. The 5w30 synthetic wasn't approved by Briggs until a couple of years ago or so and is retroactive to older engines.

I'm still leery of it.......especially in a worn engine. I'm not a fan of the rod being OUTSIDE the block....! Sounds like B&S wants to sell more engines......LOL

 

[KennyV]

I have been running synthetic 5w40 in all my engines for many, many years now, in all my engines, gas and Diesel... large and small..
For the last couple years it's been Rotella T6, 5w40, annual oil changes... :smile:KennyV

 

[JDgreen]

I have been running synthetic 5w40 in all my engines for many, many years now, in all my engines, gas and Diesel... large and small..
For the last couple years it's been Rotella T6, 5w40, annual oil changes... :smile:KennyV

Kenny, I have considered using synthetic oil but the cost scares me off, I generally change the oil in my push mowers just before I store them in the fall, and then again mid mowing season in late July, when I also resharpen the blades. Since I have to tip the push mowers on their side to remove the blade to sharpen it, it's not big deal to drain and change the oil at the same time. Since the mowers have no filter, it's easy to do the oil changes.

I know synthetics are made to prolong oil change intervals but I'm sticking with conventional oil for now.

 

[KennyV]

my gas mowers get very little use... And they have drain plugs.
So in April I will put forks on my loader and lift them up, drain oil remove and sharpen blades...

every thing gets a change at the same time... easy to remember... :smile:KennyV

 

[JDgreen]

my gas mowers get very little use... And they have drain plugs.
So in April I will put forks on my loader and lift them up, drain oil remove and sharpen blades...

every thing gets a change at the same time... easy to remember... :smile:KennyV

I have 5 pushers, ages dating from 2001 to 2010, and NONE have drain plugs, (that I know of) the engine manuals all say to tip the mower on it's side to drain. I wonder sometimes if they recommend that because the mowers don't have drain plugs, or if they think fewer people will injure themselves messing around draining oil from underneath. Later today I am going out and check to see if any of my mowers has a drain plug...

Hmm, just found the manual for the oldest one, a Craftsman...manual shows a drain plug in the engine parts diagram but same manual recommends tipping to drain oil....:confused2:

 

[KennyV]

There is nothing wrong with tipping them over to drain... Many small engines have the drain plug on the side right below the fill port... I just have the forks on at the time for lifting the decks to sharpen or replace blades... & I can bring everything up to eye level ...
:smile:KennyV

 

[JDgreen]

There is nothing wrong with tipping them over to drain... Many small engines have the drain plug on the side right below the fill port... I just have the forks on at the time for lifting the decks to sharpen or replace blades... & I can bring everything up to eye level ...
:smile:KennyV

Kenny, I cannot frickin' believe this but out of five pushers, two of which are Yard Man, one is Craftsman, one is a Brute, one is a YardPro (Husqvarna)...ALL OF THEM HAVE A DRAIN PLUG....!!!

The drain plugs are shown in the parts section, but in all five manuals, NONE OF THEM say one word about the drain plug for oil changes, they all show illustrations and have instructions about draining the old oil by tipping the mower on it's side. On the Yard mans the drain plug is a recessed 3/8 inch drive socket plug, on the Brute and YardPro you have to remove a part of the front drive belt shield near the blade to access the drain plugs. Next time I change oil on my pushers I am going to lift them up onto sawhorses and see how easily I can access the plugs. I made one pair of sawhorses really high for when I have to work on mowers, not as fancy as a FEL and forks but they serve the purpose.

 

[twall]

Kenny, I cannot frickin' believe this but out of five pushers, two of which are Yard Man, one is Craftsman, one is a Brute, one is a YardPro (Husqvarna)...ALL OF THEM HAVE A DRAIN PLUG....!!!

The drain plugs are shown in the parts section, but in all five manuals, NONE OF THEM say one word about the drain plug for oil changes, they all show illustrations and have instructions about draining the old oil by tipping the mower on it's side. On the Yard mans the drain plug is a recessed 3/8 inch drive socket plug, on the Brute and YardPro you have to remove a part of the front drive belt shield near the blade to access the drain plugs. Next time I change oil on my pushers I am going to lift them up onto sawhorses and see how easily I can access the plugs. I made one pair of sawhorses really high for when I have to work on mowers, not as fancy as a FEL and forks but they serve the purpose.

My snapper has "oil fill/drain" labelled on the dipstick, but there's a plug underneath that's easy to get to. I always use that.

 

[Mike D]

My snapper has "oil fill/drain" labelled on the dipstick, but there's a plug underneath that's easy to get to. I always use that.

This is the straight scoop --- air cooled engines have hot spots usually near the exhaust valve on the engine head. These hot spots will break down the VI ( viscosity index ) improvers over time. The byproduct of this chemical breakdown is a type of varnish, which is not a lubricant. To make a conventional ( not synthetic ) 10w30 oil it would use a 10 wt. base oil, detergent package, and VI improver. This oil will flow like a 10 wt. oil at low temperatures and lubricate the load beering surfaces like a 30 wt. when at operating temperatures. When the oil comes in contact with the hot spots the VI improver starts to break down until the oil becomes a 10 wt. oil. A 10 wt. oil will not give the engine adequate boundry lubrication and clearance to the bearing and crankshaft thus the connecting rod breaks and it's by-by engine. Period. A 10w40 oil is the same formula 10w30 with more ( 3 - 5% ) VI improver.
A straight 30wt oil contains no VI improver, therefore no breakdown. However the oil will act like molassas if you try to start an engine on a cold winter day. Synthetic oils use ultra pure components that require a small amount of VI improvers to meet the 10w30 grade. Also higher horsepower air cooled engines use pressurized lubricating systems which have larger oil sumps for better temperature control.
The bottom line -- use straight ( conventional ) 30 wt , 40 wt , or synthetic 10w30 , 15w40.
Do not use a conventional 10w30 ,or 10w40
The cost of the oil is a lot less than replacing the engine!!!

 

[Fish]

10w40 is more prone to break down against the high heat of an air cooled engine, and turn into an engine destroying goo.

Never use 10w40!