I used royal purple and the car feels great...75w-90

 

I also use royal purp 75w-90, i havnt heard anything bad about it, my pumpkin is runnin' fine but then again i dont abuse my car often.

 

i have used the rp 75w90. i didn't feel a difference between that an the oem stuff. I just switched to amsoil 75w90 and it made it feel smoother. I have also used rp in my engine and trans. I change my oil every 2500miles, and my trans/diff every 7500 miles(every 3rd engine oil change). I like the way Amsoil feels over RP and OEM.