Anyone using Shell Rotella T 15w40?
 

Its advertised for diesel and gas, costs only $14 a gallon at walmart, and some motorcycle guys swear by it. They are advertising low soot formula as a perk, is the low soot a good thing for the rotary? Is low soot like low ash which is recommended for premixes? Does low soot mean lower carbon deposits?

http://www.shell.com/home/Framework?...ellamulti.html

I use the 5w40 synthetic for my motorcycle and I also swear by it. Sorry, I have no experience with it in my 8 so I really don't have anything to contribute to this thread =P

If it does not say API Service SL or SM, then no. That page does not say anything concrete about gasoline engine use. Looks like it's really for diesel engines. There's a long standing belief among some that oil for diesel engines is better than oil for gas engines, but unless it meets the spec for what you've got I'd keep away from it.

Ken

I know the speed guys swear by the t6 synthetic, but for us its a little different.. lol

Oh wow.. ancient post.... oops

Just for the record, I use Rotella T6 5W-40 in both the RX8 and the Cherokee.