Originally Posted By: rangerfan24
Srt8 charger. We got rotella 5w-40 for it, the rotella bottle says it meets sm automotive so I think this is a good choice. However, the RT use 5w-20 and the v6 5w-30. Why? Is the 5w-40 just for show? LIke so that mobil can endorse it? There aren't too many 5w-40 oils and there is only 1 OW-40, mobil's, that I am aware of. When the warranty is up, can we go to a 10w-30 synthetic or 5w-30 synthetic or will this hurt our motor ? Thanx. Just seems wierd that the srt8 needs the 40 weight but the rt needs a 20.
There's nothing strange about it. Different engines, with different characteristics. If you want to experiment with different oils, I'd wait until the wty is expired, and I'd do UOA to see if you can spot any problems cropping up with non-spec oil.
=======================================================
Originally Posted By: rangerfan24
I have a feeling mobil is paying them to know best a certain way maybe. dunno
The most important statement here is "dunno". Which translates to "I do not know".
This comment is right up against the line of improper, and the only reason it's not across it is that you qualified it with "I have a feeling..."
It's not about EM being a sponsor, by the way. It's about accusing any person or corporation of unethical or illegal conduct without any real evidence to support the statement. I can't imagine what either EM or Chrysler would gain through the bribery arrangement you suggest. EM already has a huge slice of the market. Chrysler has enough problems without inviting investigation, or by spec-ing an oil that's not chosen for its ability to protect engines.
Let's keep it clean and not be making accusations or even insinuations unless such can clearly stand up to careful examination.