Where do you get a Mobile one rebate certificate?

got mine on line at mobils site

your engine is starting to shrink?

what does that mean?:D

just my 2 cents

I know alot of the turbo guys will use the M1 EP when they add the turbos to the ls3 -

M1 5W-30 EP has more synthetic than regular M1 5W-30 (stated on Mobil's website - they stated something like 50% more)

It has a beefier add pack

will potentially invalidate your cat warranty only - due to higher ZDDP content - many dealers could not care less

so you get less friction, beefier add pack, and more synth for a few more bucks at the risk of ruining the cats earlier. keep OCI same

BTW - all cats go sometime - just a matter of when - I heard dealers are not even nitpicking the use of oil on those issues as well - just change under warranty and call it a frickin day

amsoil is still a better oil in my mind though - not saying I'm using it though

Here's been my bigger question. How does a dealer test the oil in your car to make sure it is the right spec and weight? Oil analysis? Are they really gonna go through all that for a SES light? I do keep the receipts of all my oil purchased in case the question is ever raised but is that what it would come down to? Just curious. I think as Gemini has stated, even if the engine seized, threw a rod, etc, they still wouldn't question the oil.

when the retail cost to rebuild/replace an engine comes down to who pays for it....at this point, I wouldn't bet against GM sending a little bitty oil sample out for a what? 40 dollar cost? to prevent an X thousands gratis rebuild/replace for an engine? as they say, ymmv.

if you made a warranty claim, you would have to show that the correct maintenance was done to the car. if you change your own oil, you have to show receipts for same. if some yo-yo reviews your documentation in detail and catches the M1 Ext., they could balk at paying. what are the chances of all these events happening at once? the risk is there for you to decide what course of action is best for you.