Switching to Synthetic, what weight

[James Crivellone]

Hey guys,

With the new motor I will be switching over to Synthetic Oil, at least that is my goal.

I normally run 20W50 Castrol GTX, however what weight/brand should I use for Synthetic?

[Jordan]

I run 5w50 Castrol Syntec.

[mph]

5W30 Mobil 1 Synthetic in both my e30's, the Z3, and the Triumph.

[AdamF 88iS]

5-30 is too thin. You need 15-50 or something up in that range, especially during summer.

[KenC]

James,
I run AMS 20w50. It's worked well for me.

[nickmp0wer]

10w40 for m42?

[Mystikal]

I ran 20W-50 regular since new, then the brilliant techs at a local BMW place put in 5W-40 synthetic without warning me. Then they claimed it was the thickest they put in M20s, usually they put 5W-30 in non-tracked cars. Fucking idiots, I burned a quart every 1k miles, and spent $30 topping up before I finally got around to changing it.

I am now using 15W-50 synthetic. The engine is insanely quieter.

[b00b00]

I run 5w50 Castrol Syntec, Trac the car and don't burn any oil.

~andre~

[Charlie]

50weight at a minimum, elsewise you will be lubing the outside of your motor as well.

-Charlie