Ive read to use 5w 30 or 10w 30 which one dose GM say to use

 

Both are recommended depending on conditions.

I would recommend 5W30. It lubricates better at startup. You can go synthetic if you wish, but it's a waste of money if you change your oil at sensible intervals.

 

thanks i appreciate it

 

There will likely be a firestorm of answers like all oil threads. The recomended oil is 5W30 like stated above. The owner's manual states 10w30 can be used in hot climates. However, 5w30 covers temperature ranges for all but the most extreeme cases.

synthetics do offer slightly better wear ratings but dino oil is just fine, only you can decide if the cost is worth it.

I run Castrol 0w30 because my car spends a lot of time in the garage and I need the start-up protection.

 

I've always run Mobil 1 10w-30.

 

I run mobil 1 5w-30, the 5w-30 is what gm recommends, It be more concerned about keeping the oil clean and at the right level over worrying about 5w vs 10w. These ls1's like to use some oil so always remember to check it every week or so.

 

If you do end up noticing the oil consumption, there is a good writeup on the ls6 style pcv conversion on ls1howto.com, I did it to my car andf I noticed that it cut the consumption more then half.

 

i was looking at the ls6 pcv system was it hard to convert it

 

^ I haven't done it, but it looks like a straight forward job.

Remove intake and there it is.

 

 

im a believer in 0W-30. i could tell a difference from both conventional and synthetic 5W-30s. most of the valvetrain noise went away. and it flows better in the cold so thats always a plus