Engine Oil

[MPH]

Liveing in Tok Ak I run synthetic in everything that burns gas. My troybuilt is 28 years old and has done way to much new garden tillin though the roots and willow bushes in this area but still going, I won't add strong..MPH

[jlasater]

If you change your oil by the book, it really doesn't matter what brand of oil you use. We've all heard stories of this brand or that brand turning to cottage cheese in an engine when it's overheated, or somesuch nonsense. Change your oil by the book and your engine will live to a ripe old age. I ran straight Valvoline 40w in my Suzuki superbike when I was racing and it worked just fine. On a complete engine teardown, everything was nice and clean, and virtually no wear. Just change the oil enough and don't run it low, and you'll do fine.[A href='http://www.wheatfarm.com']http://www.wheatfarm.com[/a]

[SmilinSam]

One of my first jobs as a chemist was working in a lube oil blending plant. I worked on many different labels of motor oils and specialty oils. I now buy the cheapest API "SJ" grade oil I can find, and change oil often! Years ago there may have been a difference in the "base oils" used by different brands, but todays refining techniques make all base oils the same. Some brands, such as Phillips Trop-Artic and Amoco LDO(which were blended in the Chicago area), used to be real careful about starting with a only a base 10 oil for their 10W30 or 10W40 multi-vis formulations, but I am told that this is no longer the case. Some brands, such as Castrol, do have some Castor oil, or some other fancy additive, in their formulations, which in theory improves lubricity at high temps, but in practice it is dirt that causes problems, so nothing beats changing oil often. The API(American Petroleum Institute) sets the standard for additive packages, ususally the only difference is dye. I have never been a big fan of synthetics, but I do use Castrol Semi-Synthetic in my Gold Wing, but dont ask me why, I just do. Be careful not to use synthetics in new engines or in engines that have excessive wear, the synthetic will go right by the rings. Interestingly, the most expensive oil additive that I ever saw was in the cheapest oil I ever made -- the additive to make chain saw bar & chain oil stick better.

[JDreher]

I have '95 Sunstar with a Kohler Command V-twin engine, and the Kohler manual says for summer time use 10W-40 service class SF or SG. My understanding is that the first letter "S" indicates the oil is rated for spark engines, and the second letter "F" or "G" indicates the quality of the oil and level of additives. The higher the letter, the better quality. So, on to the questions: 1. Why do lawn tractor motors use standard automotive oil? My motorcycle uses special motorcycle oil. Is is because the motorcycle has 13,000 rpm rather than 3,200? 2. Is lawn tractor oil a lower quality oil than automotive oil? 3. Is anybody using synthetic oil in their tractor? I have had great luck with synthetic gear lube, but always thought that synthetic engine oil is too expensive relative to it's benefits. 4. I am currently using Catrol GTX service grade "SJ" simply because that's what I use in my cars. 5. I called Kohler to get their position, and they said just to follow the owner's manual, and I couldn't get them to expand on the subject. Maybe I didn't get the right phone number, anybody have a phone number to Kohler technical? Happy mowing, John Dreher

[Guest]

I doubt you will get any other answer from Kohler. Theoretically, manufacturers engineer and test every component in a product. Those manufacturers have no control over other brand oil or aftermarket filters, belts, and parts. Some other oils and parts may be better, may be not, or the quality could change.

[dmcluckie]

Unfortunately, asking mechanics and gearheads which oil is best is like asking which religion is best. It never ends well. My personal opinions on oil, not all pertinent to your questions: 1) Oil has improved but the owner's manual on a 1972 XYZ has not. Just because they didn't recommend multiweight oil doesn't mean it's not better. 2) Ditto for synthetic. It's great stuff, I use it in my mower but not my car. I think that's because I change oil in my mower but take my car to the quickie-lube. 3) If you use what's called for in your owner's manual, you can't go too far wrong. To answer your questions, a 13000 rpm 4 cycle needs better than average oil. A lawn mower needs average automotive oil, in my opinion. I would use 10W40 since that's what they call for. -Don

[Les]

Sorry for being unidentified, the last post was mine, I lost my internet connection and didnt re-log in