3,000 mile oil changes are a huge waste of natural resources. i've used mobil 1 since 1985 on VW GTI 4 cylinder with 7,500 mile oil change intervals in minnesota. after 250,000 tough miles that included autocrossing, the motor still did not move off of the full mark between oil changes. we finally retired it because of a fuel injection problem that would have cost more to repair than the car was worth. this motor worked hard for a living. it was raced and turned 3,000 rpm @ 60 mph; not exactly babied!!

 

25K on oil and 12.5K on filters--or one year whichever comes first.
Believe it, it works. All you have to really do is check oil level, since you aren't in a lube shop very often--and, you need to be sure you have the oil available for topping off. Oil analysis is definitely needed on the over 25K changes.

But if you like getting a look at the underside of your truck every 2-3 months, stay with the lube shops.

 

I understand the dual filter setup. I understand that synthetics last longer. Neither really help with the oil decompostion due to thermal cycles. My oil is always at the full marker but that doesnt mean the oil is in great shape.
On the other hand if an oil analysis says everything is good then is should be good.
I personaly notice a performance drop after 3000+ miles on my oil. The truck just doesnt act like it does with new oil. Granted its conventional motorcraft.

 

i'd say 250,000 miles on a 4 cylinder engine is a good sign that extended intervals work . . . .

 

guys... this is like the dumb movie rental places. it gets burned in your skull that the movie is due the next day.... you don't forget that and you return it on time. NOW they have this stupid 5 day rental, then comes 3 days and you forget and then pass up the 5 days and don't remember because you think you have tons of time to return the movie. they bust more overdue's on 5 day rental then they do on overnight rentals, believe me, my best friend works at hollywood video.

SO... i will stick to the 3,000 mile oil change that is burned in my skull.... otherwise i'd forget about it if i try to go over 3k.

damn movie rental place tried saying i owed 53 bucks.... no way!

 

Synthetics don't lose their lubricating properties, even with extended drains.
2 things happen with oil.

1.)They become contaminated with by-products of combustion. and either thin down or thicken up.

2.) The additives that combat the by-products of combustion get used up. Then the oil will tend to oxidize or turn to acid.

If the oil is designed for extended drains it will have extra additves in it. The by-pass filter will remove all wear cause debris, including water and fuel.
when changing the full flow filter at 6 month intervals you will be adding extra additives to replenish what was used up. Mainly TBN and ZDDP.

This is not something new. There have been by-pass filters out since the 1950's and maybe even earlier. Also now oil's are better designed to last and perform better