i just made the switch from dino to Castrol Syntec and my motor is 10 times Quieter and smoother also I have picked up another 4mpg <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> anyone else notice this? also for you guys runing syn. in higher mileage engines that burn a little what does it leave behind for deposits the reason I ask 2 of my other toys are Mazda RX-7's and the rotarys in them have an injector pump that meters oil into the intake to lubricate the rotors so synthetic has always been black magic with them. <img src="/forums/images/graemlins/evil.gif" alt="" />