So for some reason I am concerned that my dealer put the wrong oil in my LMM. I may be paranoid, but this same service department didn't know what coolant was supposed to be used in the LMM earlier. I asked them to leave me a half empty bottle in the truck when it was done so I could make sure myself, but they didn't. I called them on my way home and asked what oil they used, the service guy called me back and told me the tech said it was a blend! Real useful info there! No brand, no idea if it was CJ-4.

I want to do it myself, but with no garage, lots of rain and no place to work on it, it is difficult.

How would I know? Truck seems to be running different and smells different but then again it could be in my head.

What do I do?

Call service manager - Ask what rating (don't tell them it should be CJ-4, make them tell you what they use in the new diesel trucks). If they can't tell you CJ-4 then they need to make it right.

PM sent with dealer recommendation for GM Quick Lube and for your TPM reset post to.

;)

http://pictures.dealer.com/vestalcars/b53f779140463872009e75f65ea38d33.jpg

You won't be able to smell, hear, or otherwise distinguish the difference between a CI-4+ oil and a CJ-4 oil. UOA tests would show you, but that would cost you, and you'd want a TBN test included.

If for some reason, they mistakenly used non-diesel oil, you won't know the difference either, but your engine would not fare well over time.

All oils are "blends" of stuff; none are "pure". They have base stocks, additives for VII and such.

They most likely used a reasonable oil. However, I'd be honked off if I paid for 3 gallons, but only got 2.5 gallons. That drives up their profit margin, and then makes you go find more oil for a "top off". If they don't treat you with respect, then move on.

Time to search for a different service.