Mobile 1 has been proven to not perform well in our engines time and time again. Well besides 0W40.. I'm not entirely sure about EP. I heard that it's better, but I still wouldn't use it in my car, but I would NEVER use any oil for 15k. That just seems way too much.

I'm sure some people have done UOAs on that haven't they? The max I will run will be 10k and that's with German Castrol full synthetic.

 

I'm very happy with Castrol Syntec 0w30 European formula (fully synthetic) Usually sold at Autozone

I get excellent gas millage and at 130k my G purrs like a kitten.

Oil change every 5k

 

M1 is all I used for the first 60K, never had a problem, never used oil, not even a tablespoon and I ran it hard.

 

I hope you ran a UOA on that 15k OCI.

 

Look at it this way. By waiting as long as possible between oil changes, the accumulation of metallic debris in the oil will polish the inside of your engine allowing it to operate more efficiently in the long run...

 

This statement is dumb, why do you think cars have filters? So that the metallic debris is filtered out. As long as the oil still has additive and wear looks good in a UOA then you are good.

 

^I guess you missed the sarcasm... Besides, the filters don't stop everything

 

the oil will last but the filter probably won't unless you switch to a fleece based filter. Lot mercedes and BMW's have 10-15k oil change intervals but they use fleece based filters, not paper or cotton ones like everyone else use.

 

Hell, I had a Ford 9N tractor that I didn't change the oil for 20 years. All I did was add a quart when it needed it. Didn't even change the filter and it ran fine when I sold it and it's still running.