Best weight of oil?

[Tim Barnum]

I was just wondering what is the best weight of oil to use on a Buick turbo v6? I've always used Mobil 10/30. Thanks Tim

 

[Robes87GN]

I have always used mobil 1 5w30. I was told you could even drop to 0w if you wanted to. Also, instead of adding that 5th qt of oil, add lucas oil treatment. **** works, believe me.

 

[turbo nasty]

I use Castol or Valvoline syn blend 20/50 in summer and 20/50 with 2 qts of 10/40 in the winter.

 

[Tim Barnum]

I may try Lucas on my next car. It will have my stage 2 block in it. I've just been using what the GM says to use on my current car. I was just wondering if there was something better then GM specs. Thanks Tim

 

[d0n_3d]

Mobil 1 synthetic for higher mileage engines here...10w30

 

[Mightysix]

Casteroil 20/50... Nice and smooth