Which weight synthetic oil?

[RWEST]

Too bad theres no retailers anywhere near me.

Check with the local diesel shops (tractors or trucks). According to Schaeffer online, there were no distributors near me either, but when I mentioned their products at the local JD dealer, they directed me to a guy who was nearby. Don't know why he wasn't listed at Schaeffer's site.

Schaeffer has a very good rep amongst the guys at BITOG.

 

[coobie]

I looked up the specs on schaffers and they look really good.Too bad theres no retailers anywhere near me.

Give this guy a call Gene Schubert ph#419-658-2258 he is a super person to deal with.He lives in Ney,Ohio.Maybe he can direct you to a local guy who sell schaffers products.coobie

 

[Blackbird_BX]

Thickness of the oil at operating tempertures is not the advantage with synthetics, film strength is, and it's resistance to shear. The connecting rod bearing surface is the maximum load an engine sees, and the synthetic oil's 3 to 4 fold resistance to shear over a conventional oil is where they shine.

That supports my understanding is that the best oil for an application is the thinnest oil that sustains film and resists shear in operation with a margin of safety. If it was possible to formulate a 0W-0 oil that maintained the desired film between moving parts under all operating conditions in an engine, it would outperform 15W-40 with the same film strength and and resistance to shear. There should be less friction, thus higher fuel economy and cooler operating temperatures.

I have anecdotal evidence of the effects of using higher viscosity oil than necessary from what I've observed in both a Chevy Sprint ER and Geo Metro I owned. Because of the small 3 cylinder engines and ~50 MPG average fuel economy, both vehicles gave a lot of feedback if operating conditions were less than ideal and I put over 30,000 a year under warm to hot conditions. Both cars would quickly tell you if they didn't like something. The wrong oil, tires, low tire pressure, ect. would result in obvious changes in engine operating temperature and fuel economy. In those rare occasions I let someone else change the oil and they put in 10w-30 instead of 5-30, it was immediately noticeable. The engine would run significantly hotter and fuel economy would drop by about 5 MPG due to the engine having to deal with the thicker oil. When I switched to Mobil 1 0w-30 from Mobil 1 5-30 on the Geo at around 100,000 miles fuel economy increased operating temp dropped by about the same rate. Not long after that, my mother started driving the car and annual use went down to under 1000 miles/year. When I sold the Geo with 170,000+ miles on it years later the engine was still running like new. Compression was still in the high end of normal and no measurable oil consumption between oil changes. The only work ever done on the engine other than preventive maintenance was replacing the water pump around 170K.

 

[jayhaitch]

My experience exactly. My wife's old Toyota Corolla noticeably increased its fuel consumption when the air filter was dirty.

I have an 86 Porsche 911, eurospec Carrera, purchased 4 years ago. I began to use Amsoil 10W-40 after my first oil change, every fall. I got off kilter and didn't change the oil until spring last year, so I just ran Castrol until the fall oil change. The oil viscosity chart for the 911 is rather confusing. I didn't think about using diesel rated oils, so I used Castrol GTX 20W-50. Poured like molasses, and noticeably slowed the rise of oil pressure upon startup. Once the Amsoil 10w-40 was back in, oil pressure shot up immediately upon starting, and all pressures stayed at lower levels.

So despite 20W-50 being acceptable based on the owners manual, it was actually too thick for our 70-90F summers.

 

[hotchkiss]

Has anyone used or researched Red Line 15W-40 oil for deisel engines???? If so, let us know what you think. I used it in my last tractor because the prior owner had always used it and I couldn't find any reason not to continue using the same oil. With a new tractor, I am also trying to decide what oil to use.