Engine/Transmission (1998.5 - 2002) Amsoil weights vs mileage

[MichaelRyan]

Hello,

I used to use the 5w/30 amsoil diesel oil - BUT it seemed it used a little more oil. Like around 1 qt per 2000-3000 miles. I went to the 15/40 diesel oil and oil consumption went back to about 4000-5000 miles per qt.

I am not sure if the oil consumption is normal for a truck with about 100,000 miles on it.

Anyone have any experience with how much consumption is normal.

The gotcha here is that the mileage was significantly - probably about 10% better with the 5/30. I was thinking of switching back.

Truck runs fine with either weight probably a little stronger with the 5/30.



MBR

 

[FLynes]

Michael,



I use 15/40 exclussively and have never had any oil consumption whatsoever, but then again I change my oil every 3,000 miles religiously.

 

[rjrkihap]

MBR,

Same for me (no consumption at 115K) except I run Valvoline PB Extreme 5w30 and change the oil and filter every 6,000. Had a friend with a similar issue and Cummins told him to stop babying the motor and work it so it will seat the rings.

Good luck

Ron

 

[MichaelRyan]

I use the bypass system and don't change but every 30K. I do oil analysis every year or more. The last analysis showed zero wear metals.

 

[Vaughn MacKenzie]

I ran the Amsoil 5w30 once in my 2001 when it had ~50,000 miles. It used some oil, I think a quart every 3k as I recall. With the 15w40 it was virtually no usage.

I sampled oil on my '01 regularly and wear metals went way up with the 5w30. But part of the problem was the weather got too hot to be running that oil, it topped 110 degrees here that summer.

I didn't notice any mileage improvement, I'm definitely not running it again, not cold enough to justify it.

 

[Slingblade]

I changed to Amsoil last fall. It's been about 4500 miles since the change and it has burned off a quart so far. I'll have to go look at the spare oil in the garage as I can't remember the weight. I think it was 15-40. I normaly use valvoline premium blue with no loss of oil. I just picked up three gallons of rotella last week and as soon as the weather gets a bit warmer I'm changing back to regular dino oil with changes every 5,000 miles.



I remember when my '01 was in the shop for a lift pump. The mechanic that was working on it used to work for Cummins. His old boss came in and saw the Valvoline premium blue extreme synthetic jug in the back of my truck. He recommended that I not run it as Cummins found that it "oozed out" and did not provide good bearing protection and tended to get past the rings easier. I still ran it in that engine without problems though. Just what this guy said, I'm not bashing on synthetic oils.