when i bought my ram, it came with penzoil dyno oil. the truck had been sitting in the dealership's lot for over three months so i changed the oil a week after i got it with castrol gtx and fram filter. well 2500 miles later, i have around 63.5k miles on her. i went to auto zone the other day and bought a case of mobile 1 drive clean plus high mileage synthetic blend, you know the mixed stuff, and a k&n oil filter. i figure going right to synthetic would be a shock to the motor so i'd like to flush out the old dyno oil first if that makes any sense. what i'd like to know is, is this a good idea? how many of you have done it this way? what were your results?

 

I run synthetic in all my rides. No problems as of yet and I've been using it for about 10 years.