Would like to start using synthetic oil in my truck, just want to make sure to not mess it up. Is there anything I need to do special during the oil change?(specifically to flush out old oil). I have 140k on my motor and bought it used so I am not sure what oil the old owner used. Can I safely switch to synthetic? Thanks for your time---Stan.
Yes you can. The best regularly priced syn. oil I've found is Rotella T-6 5w40 at Walmart. However any major brand API CJ-4 rated oil will be fine if you find some on sale. If need be you can also switch back with out any harm to your motor. Just for your reference the 6.0 retains approx. 4 qts. of oil in the engine when doing an oil change. Make sure you use only OEM filters in the 6.0. She don't like A/M's.
You should have no issue at all just it change normally using OEM filters, no special procedure. You will never get all the old oil out so don't worry about it, it wont hurt a thing. I use Rotella T-6 5W40 and my truck loves it especially in the Canadian winters.