I've been using mobil 1 5/30 for the whole life of the car. It has almost 80k on it now and it gets driven hard. Should I be switching grades with the miles I have on it? Is amsoil a better oil? I've heard people getting quieter engines from amsoil?

 

usually in colder climates people run the 5w30 and hotter areas run 10w30. or you can switch from winter to summer months. I say just keep what your using its a good oil.

 

Mobil is good oil, but I would recommend a diff viscosity. 5w30 is on the thin side with the mobil. I would recommend the 0w40, or I have heard they have a new 10w40 now in the new formulas.

 

10w40 is what I was thinking I should be running

 

10w30 isn't recommended either. The european formula 0w40 is supposed to be the best mobil 1 viscosity unless they have developed something better since.

 

Mobil 1's best oil is their 5w40 actually.

 

I've been using the 5w-40 for a while now with no real issues. I don't do the analysis thing so couldn't give you any numbers. It's starting to get cold here and I have a bit of a knock when it's first started. It goes away before long, though.

 

Is that available at Wal-mart or what? I guess I haven't seen it yet. I have been running their 0W40 for quite awhile now and haven't had any problems.

 

When did this become available? I have been using the 0w40 for over a year now because it's what you always recommended as far as the Mobil 1. I assume it came out around the time all this "extended performance" oil came out.

A little more info please...it's not too long before my next oil change, it'd be good to know what's currrently the best for the LS1 that Mobil 1 has to offer.

 

It's been available for a very long time actually, it's original form is Delvac 1 5w40, which is a fleet oil that has been used by truckers for many years. Now it's repackaged as Truck & SUV 5w40. In that form, it's been out for a couple of years now. There is some discrepency as to whether or not the two oils are identical, but based on virgin oil analysis they both look to be the same.