Damn good information JMatt. When I saw you started YET ANOTHER "thread that just won't die." I knew it must have been important for you to post it.
I'm a little leary though based on my climate. It gets below zero at least a few times a year.
My SRT10 also takes 0w40 so I'd like to consolidate and buy in bulk for both vehicles. I could see putting the 5w40 turbo diesel Mobil1 in my SRT8 since I don't drive it on such cold days.
What do you think about Chicago weather and my truck though? Since the rating is 0w40, and it can get -5 to -10 the factory rating is already too high. Maybe 5w40 isn't something to be too concerned about???
My Dakota was rated at 5w30
