if your cars in good shape get the synthetic, if it leaks or burns oil stay with the conventional stuff. but if your gettin the castrol for free go with that
definately full synthetic. if not for the additional ponies, then do it for the additional protection. conventional oils are supposed to be good for ~3k miles while synthetics are said to be good for ~6k-7k miles. also synthetics can handle extreme conditions better (ie overheating etc) and don't break down as easily so they'll leave less sludge in your engine.
FWIW when i swapped my whole drivetrain for synthetics the difference was HUGE. the car pulled harder and smoother.
If I want to change from conventional to synthetic is there anything special i need to do?? Does it need to be completely flushed out before hand?? Should i fill with synthetic, run for a while, then re-change it??
definately full synthetic. if not for the additional ponies, then do it for the additional protection. conventional oils are supposed to be good for ~3k miles while synthetics are said to be good for ~6k-7k miles. also synthetics can handle extreme conditions better (ie overheating etc) and don't break down as easily so they'll leave less sludge in your engine.
FWIW when i swapped my whole drivetrain for synthetics the difference was HUGE. the car pulled harder and smoother.
I have some dyno runs of synthetic vs. conventional oil. I need to find them, but the conventional oil made about 2 more hp than the synthetic, while the synthetic made about 2 more on the low end. basically they were a wash power wise.