Maybe. API has tested oils off the shelf that was API Certified, yet did not meet API spec. Valvoline and Castrol tested Mobil 1 5w30 off the shelf and it did not meet the API spec. Mobil 1 5w30 is on the GM approved list. Since it did not meet the API minimum spec, how could it meet the GM spec?quote:Originally posted by ADFD1:quote:
They can, and do, require whatever oil you use to meet said specs for warranty coverage.
I haven't seen any owners manual that says "Use whatever oil and or weight you want."
BINGO, I thought I was the only person who realized that! Thanks Man. Bottom line pick an approved oil from GM's list if you own a GM. If you have a problem and follow GM's recommendations you'll be fine. Even cheap no-name oils are on the list, so price and availability is no problem!
Again, here is what GM has to say about oil and warranty:
“The New Vehicle Warranty would not be void simply because an owner failed to use proper engine oils or did not perform maintenance at the prescribed intervals. Warranty applicability is contingent upon the cause of failure.”
Service Policies and Procedures Department,
General Motors Corporation “
Personally, I'd rather us a better oil than one that barely meets API and the GM spec. So that is what I do.