Appropriate Engine oil for C6, please advise...

[Patman]

One of the reason so many LS1 owners have oil consumption is because they're using M1 5w30, which is too thin for the LS1/LS2/LS6 family of engines. I know quite a few owners of these engines who switched from M1 to something slightly thicker and saw a nice reduction in consumption.

My 98 Corvette's engine uses no oil between changes, even when I go 8000 miles. I'm using German Castrol 0w30.

 

[NewC6]

Hey Patman, any idea if the newest Amsoil oils are going to be too thin like the Mobil 1 stuff is now? I like Amsoil but if its to thin, will stick with the Green GC until I run out.

 

[Patman]

Amsoil has reformulated it's 5w30 and 10w30 a bit thinner now, and for this reason I would recommend that LS1/LS2/LS6 owners go with their 5w40 instead.

 

[Tak]

But hey, in an new car, thinner is better if the HTHS rating is the same... no? arent we talking about better MPG, HP and lower temps?

 

[AndyH]

But is the HTHS rating the same?

 

[Tak]

Andy,

You may be right that its not the same HTHS, im just saying that its not the "thinner" property of the oil that should make you move a step up to the 5w-40... its the other ratings and factors that matter...

Since redline managed a 3.8 HTHS, im happy with the 10w-30

 

[Patman]

Amsoil did drop it's HTHS rating a little bit on the newly formulated oils.

 

[buster]

Very little seperates Amsoil ASL/TSO/ATM from any Mobil 1 grade other then Amsoil doesn't retain it's viscosity as well and that is pretty much a fact at this point.