Just FYI, when there is a number like 5W-30, 0W-20, etc...it denotes a non-Newtonian nature of the oil. It means viscosity increases with increasing temperature relative to that of a Newtonian oil that has the same cold viscosity of the non-Newtonian oil. You don't need to be adjusting the weights of the oil you put in based on temperature because the oil already adjusts for you. Seems like those engineers think of everything, doesn't it?

I personally go with higher viscosity when I know I'm going to be making a lot of torque on an engine that wasn't designed for it. Thin oil is displaced more easily than thick oil, so it follows that high bearing loads from exceptional cylinder pressure is going to warrant the use of an oil that won't get squeezed out as easily. I haven't seen any quantitative testing on that...just following my intuition on the matter.

Looks like I ran through my 2 year supply of oil changes in about... 9 months. Tried to take it in for my third free change and the wait for a 7:00am appointment made three days prior was two hours. So I asked the guy how many free oil changes i had left and he said this one, by the time I need the 4th I'll be past 24k.


Rumor has it this beast takes 8 GD quarts of 0-20, about to find out if my Walmart has it in Mobil one synthetic.
Dealer uses a synthetic blend. I wonder what the change interval should be using full?

Base that on what filter you buy too.

I'd run a full syn with a quality filter 5-6k miles no problem. If all you did was straight freeway all the time with the motor always up to temp and allowing the oil to stay hot and do it job correctly, then hell even 7k miles with a good filter should be fine.

I'd even go as far as testing the oil and having it sent in to Blackstone Labs. They can give you all the info about how much life is left in the oil, they charge a small fee but atleast you know whats going on inside your motor. The will ship you a free test kit which is nice.

I am at 22k right now, I'm going to take mine in at 23,999 or as close to that as possible (while still under of course) and have my final one done.

I figured I'll use a full syn and the good k&n filter since I get them free… haven't decided which brand to run yet. does it have to be dexos based or whatever?

It has to meet Dexos standard.

I have M1 0-20 in mine.

amsoil exceeds dexos standards..
thats what im goin to run,

-Nate

I guess my question is… why… what do the dexos standards have to do with how any specific oil works in an engine?

I use it because the manual says Dexos standard is required and I dont want any warranty hassles should something arrise. As for what difference it actually makes, I would imagine NONE as far as how the oil works. I see it as more of a money maker then anything for GM as now companies have to pay them to advertise that they meet that standard. It doesnt cause me anymore hassle to use a "Dexos" oil when I change the oil so whatever. No doubt it drives up oil cost though as now companies will pass along the added cost. Mines all stock and is staying under warranty till its up.

"Fortified with detergents that exceed dexos1 sulfated ash specifications"

straight off amsoil site.

+1

-Nate