Gonna try M1 Truck & SUV in my 8.1 gasser

[Jelly]

quote:

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Originally posted by Stewart Fan:
There are very few UOAs done on the 8.1 liter gas engines from GM. All the UOAs have been on M1 10-30 IIRC. Although my truck calls for a 5-30/10-30,I'm going to try the 5-40 M1,and post a UOA in a few months. I don't see an issue with the higher viscosity. A COLD winter night around here is 25-30* Fer. The average overnight lows are around 40*.

Do you see any reason not to try it?

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Nope...in fact, I strongly recommend that you run a 40-weight in that engine!

 

[heyjay]

Stewart:

Is your Vortec 8.1 one of those infamous oil burners? In that case, the Mobil 1 Truck & SUV 5W-40 (Same as Delvac 1 for commercial trucks) will HELP a lot.

I know in my commercial equipment, oil consumption decreases around 50% on average.

I will also be switching my truck to M1 T&S in April or so. If Holden in Australlia can run LS1's with xW-40 and xW-50 oils no problem, with MUCH lower oil consumption, we can too.

FWIW: here is the difference viscosity makes in my 2000 GMC Sierra with Vortec 5.3 V8:

Mobil 1 0W-30 1 quart every 4,200 miles
Mobil 1 5W-30 1 quart every 4,800 miles
Mobil 1 10W-30 1 quart every 6,800 miles

I don't think there will be any negative fuel economy hit. I used to have a 1992 Honda Prelude SR that I bought new.

In summer of '94 (Or was it '96??) I put in Delvac 1 5W-40 before a very long road trip. I went to Lost Wages Nevada, then visited some relatives in Santa Rosa CA, then down to LA, then across the South to Disney World , back across the South to I-35, then North to home.

There was NO difference in fuel economy. The motor seemed a little quieter and smoother. Not an oil burner to begin with, there was a DRAMATIC difference in oil use: 15,000km on the oil and the level was down about 2mm on the stick.

Jerry

 

[Stewart Fan]

I wouldn't call it an oil burner. It does use some oil,usually about 1/2 qt. in 3500 miles. I don't consider that unreasonable,because I work my truck alot. I tow our boat almost every weekend,and then our travel trailer the times I'm not towing our boat.

 

[Stewart Fan]

There are very few UOAs done on the 8.1 liter gas engines from GM. All the UOAs have been on M1 10-30 IIRC. Although my truck calls for a 5-30/10-30,I'm going to try the 5-40 M1,and post a UOA in a few months. I don't see an issue with the higher viscosity. A COLD winter night around here is 25-30* Fer. The average overnight lows are around 40*.

Do you see any reason not to try it?

 

[C T Puchniak]

Here is the results of my 8.1 L Avalanche

First 6000 miles on dino 5w30---no burn at all

Changed to Castrol syntec 5w50--burned 1qt/300 miles

Castrol syntec 10w30--1qt / 600 miles

Tech 2000 10w30--- 1qt / 800 miles

back to Dino 5w30--no oil burn at all

Now on GM oil burn watch--rather embarrassinng no burn

Figure that one fellas!??

Clare