Worth looking at, here is a man that is well informed: Worth a paste: When two companies lock horns the end result is the customer is without a vehicle. Get a lawyer involved be prepared to pay.
It is always best to stick with the mfg suggested oils and change oil when the mfg suggests changing oil. They designed the engine.
Pasted from the link.
Gosh - here's a real life example of what I've often touted about the misconceptions of the M/M Warranty act. In a nutshell, I can summize.
If you use the prescribed fluids in the prescribed manner, then the burden of proof is upon the OEM to show that your actions somehow caused the failure of the product in question. If you have good, solid evidence to show that you followed warranty parameters, then most OEMs won't even argue with you. If you use alternative materials and/or methods for maintenance, then the burden of proof is upon you to show that your selections did not cause the failure. It's that simple on the surface; use their specs and they have to show it's not their fault - use your stuff and it's up to you to show it's not your fault.
After reading this who needs the hassle if there is a problem?
Keep life simple take the path of least resistance.