i recently just switched over from dino to full synthetic and i went for the mobil 1 extended performance which is guaranteed for 15k miles. is this to be trusted or should i stick with the usual 7.5k miles. the mechanic at the shop actually told me even with full synth he changes his oil every 2k miles!

 

I don't think you will have an issue going 15K, but for peace of mind I'd run a Used Oil Analysis at 10K to see how the oil is holding up.

You might also want to do some research over at the Bob Is the Oil Guy forums and look at UOA's of extended life oils.

 

The extended performance is the "original" Mobil1. If you do decide it to go the full 15k miles, be sure to change the oil filter half-way ... the oil should last you to 15k.

 

thats opposed to the "new" mobil1? whats the difference im just curious.. is it better or worse?

 

The extended will last. If its your first time i would have a sample taken at 7500 to 10k and sent to blackstone labs to be analyzed. I would continue to do so every so often and see how the motor and oil is holding up. I was able to get 15k out of it.

Oh and find a different mechanic if the one you went to changes his syn every 2k

 

haha duly noted!

 

I use the same oil to 12K-15K each change with a Denso oil filter. I would say anytime near 15K should work.
I agree with the earlier posting, if you are worried there are many testing places that will tell you if the oil is breaking down and may let more wear occur.
I've been changing at this interval for about 2 years now, car is at 83K and runs very well still.