I have a 2003 3.9 Dakota. I am thinking about using RP or some other syntheticin my automatic tranny and my axles. has anyone done this and if so how did it work? What did you use to flush the systems??

 

I've used it, no difference. In my engine it actually made it idle funny. I went back to conventional oil and it's doing just the same (about half the price) In the axles there wasn't any diffenrence either. Don't waste your money.