Engine Type of Oil for Push Mower

When my Exmark with Kawasaki engine was new, I took it back to my dealer, who charged me $8/quart for Exmark SAE30w oil. Next time it needed changing, he told me, "You can change it yourself, if you like, using any brand of 4-stroke SAE30w oil". I appreciate his honesty and now change my mower oil each season, using Castrol SAE30w oil from WalMart. I would never want to use 2-stroke oil in my mower engine. I think it's too thin.

deriter said:

Cain't believe I read this whole thread. What in the world does that mean?

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It shows that the advertising that no one is ever influenced by has confused 1/2 the population and the other 1/2 are all "experts" in something they know next to nothing about.
Thus in the manufactured confusion some oil vendors are making a fortune.
Dad used to have a fixed reply for people with oil fettishes.
"You know what the absolute best oil is,,,,,, the stuff you just changed "
There is no such thing as changing your oil too often, engine love clean fresh oil.
The only thing a consumer should worry about is selecting a viscosity that is within the engine makers parrameters for the temperature ranges the mower is used in.
After that is is just a matter of actually checking it.

somewhere around page 14 I burned out on reading. Was trying to see if there was an article whether detergent or non-detergent SAE 30 worked best in this old edger but since we had chicken tonight I think we'll just use the old Crisco after straining it. :laughing:

sgkent said:

somewhere around page 14 I burned out on reading. Was trying to see if there was an article whether detergent or non-detergent SAE 30 worked best in this old edger but since we had chicken tonight I think we'll just use the old Crisco after straining it. :laughing:

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Well the answer was there

Detergent oils for engines with disposable filters
Non detergent oils for engines without disposable filters.

The only purpose of detergents is to hold the crud in suspension for long enough to allow the filter to remove it

Sorry Bert, have to disagree with you on this one. Detergent oils should also be used with small engines with no filters. As you said the detergent holds the crud in suspension so it can be removed when changing the oil. This is the reason you must warm up and agitate the oil before changing.

I think we can dissagree on this & still be friends.
It will depend weather you consider the sump to be a setteling tank or not.
In any case, finding a non-detergent oil now days is near impossible as it is only made for vintage dry sump engines and some very large dry sump marine engines.
It is also more expensive than regular engine oils and all mower oils we can get down here are detergent.

With a detergent oil there should be little requirement to run the engine prior to changing as in theory all of the crud should be in suspension and not sludged out on the bottom of the sump.
However mixing it up and heating so it runs free is a good idea.

For interest, do you know of any non-detergent lawn mower oils ?
I don't which is one reason why I find these sorts of posts so amusing.
People argueing in ignorance with great passion about a package that is not available for the end use they intend.

Here in the US Menards carries a 30wt non-detergent oil in their mower oil section. Probably not a big seller, or a non seller actually. Might be good for use in some gear boxes and general lubrication? Oil selections have been argued to death lately, darn near impossible to actually know what oil has what additives, and what motors need certain additives.

tom3 said:

Here in the US Menards carries a 30wt non-detergent oil in their mower oil section. Probably not a big seller, or a non seller actually. Might be good for use in some gear boxes and general lubrication? Oil selections have been argued to death lately, darn near impossible to actually know what oil has what additives, and what motors need certain additives.

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What is happening is EPA regulations keep on getting tighter for things that do not matter nor make a difference.
So oil formulations need to keep changing
All of the oils with a primary viscosity of less than 10 were developed to reduce drag on CAR engines so the engine fires on the very first piston that comes up to TDC firing stroke so there are almost no unburned fuel released into the atmosphere.
Unfortunately very low viscosity oils drain almost completely so things have to be added to make them stick to metal bits to avoid a dry start if the engine has not been run for a while.
Lead, Copper and now Zinc have all been added to the EPA's "devils metal" list so have to be reduced or replaced all together.
What generally happens is they get replaced with something 20 times worse for the enviroment but it takes the EPA 10 years to work this out so they eventually ban that and the cycle continues.

Eventually the EPA boffins will catch up with reality and work out the old formulas were best and the enviroment can handle the contaminants provided they are not dumped in massive amounts.
There are bacteria that consume oil, quite a few of them but the dispersants that we put on oil slicks so they don't look bad kill off the bacteria.
This is of course along the lines of "if you can not see it , it does not exist " theory of pollution.
There are also fungi that consume oil which like the bacteria are also killed by the dispersants we use to break up spills & slicks.
The fungi are safe for cattle to eat and then the pollution no longer exists because it has been turned into food.
However solving any pollution problem is not part of the EPA's charter and of course would put them out of business.

yep detergent. Found it a few minutes ago in the fine print in the old manual. Thank you to all who replied.

Re the fungi and bacteria. There was a You tube at one time of fungi eating an oil spill in the Pacific NW. What was a messy pile slowly returned to green plants when it was done - about 3 years. Amazing to see. Nature has been dealing with oil seepage for a very long time.

Re the Zinc etc. It damages catalytic convertors but not as fast as lead does. People want 100,000 miles out of them and complain to their government officials when they go bad every 40,000 miles. The government then passes EPA rules to make the convertors last longer.

Yep,
Go to any petrol stations ( filling stations to some ) in rural areas where there is a significant area that is unpaved.
Plenty of grasses & weeds growing quite happily in "highly contaminated " soil.
If the station closes down the EPA will require the top soil to be taken away& incenerated because of al of the "highly toxic" heavy metals.
Yet plants grow quite happily, bees & other insects feed on the plants quite happily , catipillars will eat the plants and turn into moths & butterflys but apparently should you build a house on it and grow grass, your children will grow 5 sets of genitals if they are allowed to run over the grass.