Got the vehicle history on my 2004 s60 with 87k on it and I noticed it has been getting oil changes using castrol syntec up to 69k. Well I bought the car with 86k and got an oil change done and they used castrol gtx. Of course I didn't know that synthetic was being used before since I just got the history on it today. I know you shouldn't go back once you use synthetic but it's already been done. What do you guys recommend I do about the oil now or in the future?

 

read any of the hundreds of oil threads.. search is a magical function..

 

Yea I did, found some stuff on mixing synth and reg oil implying that its okay to go back and forth between the 2. I'll just go with my budget next time and if I can then do synthetic. I'm good about keeping up with maintenance so that's not a problem, I do mine every 2,500 miles.

 

The most important thing in my answer is that you change the oil in a reasonable interval whether Synthetic or not.. Keeping an oil with a viscosity property is really the thing that keeps the motor running. Some will say fossil, some say synthetic. I live in Florida and current daytime temp is about 103 deg. So I make sure that my Coolant is fresh and my oil changed every 3,500-4k max with Synthetic oil. Personal Preference. IMO, if you can afford synth, then why not but it's not a requirement... Here's an article another member posted this a while back... Good Luck in your search. http://www.popularmechanics.com/automot ... 32672.html

 

very good oil resource

http://www.carbibles.com/engineoil_bible.html

PS. Mixing is not a sin, thats why they sell synthetic blend....