Originally posted by: Indyboy2
I do this for a living and these are from my personal Experience ,I am a tech at a fleet management shop.I have spoken to oil and filter reps from all over .IT boils down to filtration period.If your oil is free from Contaminates excessive combustion gas,fuel,metal, then all is good.If your engine is running correctly and has no internal problems (oil analysis will show this)copper,lead,tin aluminum then 15k or around 15k is fine with filter changes .Changing your oil every thousand miles is just plain uncalled for"your case might be different" unless there is a internal problem in the engine .If we went by your schedule we would be in the poor house .You do have to check your oil with anylasis that's correct
Over the road diesels you can go 25,000 miles on a Dino oil change up to 50k with syn oil and thats a 600hp over the road turbocharged engine running 22 to 25 psi of boost day in and day out the engine is under the worst conditions there is granted it does hold alot more oil .We run our fleet cars every 7500 miles with recycled oil and alot of them have 150,000 plus on them with the internals never touched.
Just to give you a example of a car that has a 18,000 mile oil change interval porsche 997
Now why does a car that cost around or over 100k have a oil change interval like that?.Maybe their oil filtration system is very good or the engine has a superior oiling system.I can understand a drag car or something that is used in a VERY dusty conditions but for a run of the mill over the road car or truck with full syn oil with one filter change 15k will be fine as long as the oil is spec for that and it has the proper oil filter,no no-name brands But I will say if your car is new and you want to keep the warranty on that car you had better go by the manufactuer recommended change intervals.Most are 7500 miles but check with your dealer or manual
to the op dump that k&n oil filter im not sure about this but they are around 20 micron thats pretty high the lower the better mobil 1 oil filters are around 10 micron the k&n will flow more but filter less
interesting read
http://www.theautochannel.com/...00919/press025973.html