“That's just it. I was making a point NOT to believe it.
Tell me, please, what's wrong with my Dexos Q? GM states to keep a GM engine under warranty you must use Dexos oil. Why? Does other oil cause the problems I listed in my Q? Or, is it just to SATISFY GM?”
I cannot tell you why. GovMo set the specs with their testing. No oil company reveals their formulas, even pre-dexos. The simple answer is to run the spec as written in your owners manual.
In most cases, whatever your manual states should be a good guideline to start with. If your situation or climate convinces you to use something else then by all means go for it. It’s your vehicle, your choice.
Sorry I couldn’t give a straight answer.
Tell me, please, what's wrong with my Dexos Q? GM states to keep a GM engine under warranty you must use Dexos oil. Why? Does other oil cause the problems I listed in my Q? Or, is it just to SATISFY GM?”
I cannot tell you why. GovMo set the specs with their testing. No oil company reveals their formulas, even pre-dexos. The simple answer is to run the spec as written in your owners manual.
In most cases, whatever your manual states should be a good guideline to start with. If your situation or climate convinces you to use something else then by all means go for it. It’s your vehicle, your choice.
Sorry I couldn’t give a straight answer.