5w20 in a 1978 Amc Concord

[Zaedock]

Originally Posted By: SlantyNW1990
0w10?where the heck is that found?


It was a custom oil made by a member here. I'd be willing to bet it was more robust than a 0W10 racing oil.

Originally Posted By: KCJeep
I've never seen a UOA for a 258 that old, but the Jeep cousins/descendants of that engine display higher wear numbers on thinner oil, particularly aluminum. They just aren't made for it.


I have never seen elevated Al in any of my UOA's, even running 5W30 for a couple year interval including Moab. Typically, Fe is the number that goes up, but no one knows for sure where it comes from. IMO, it's from the timing chain, but that's only a theory I haven't had time to test.

 

[KCJeep]

Originally Posted By: Zaedock

Originally Posted By: SlantyNW1990
0w10?where the heck is that found?


It was a custom oil made by a member here. I'd be willing to bet it was more robust than a 0W10 racing oil.

Originally Posted By: KCJeep
I've never seen a UOA for a 258 that old, but the Jeep cousins/descendants of that engine display higher wear numbers on thinner oil, particularly aluminum. They just aren't made for it.


I have never seen elevated Al in any of my UOA's, even running 5W30 for a couple year interval including Moab. Typically, Fe is the number that goes up, but no one knows for sure where it comes from. IMO, it's from the timing chain, but that's only a theory I haven't had time to test.


A well respected member here who now is gone (RIP) ran PP 5w20 in a 4.0 for a test years ago. His iron was normal, but Al was quadruple the universal average. My first UOA I ran a blend that turned out to be a 20 grade by accident, and my aluminum was triple the average.

My second UOA was a light 40 grade and my aluminum was only 1 ppm, 1/3 the average. Quite an improvement! Iron was higher on the thinner lube as well but nothing real excessive.

 

[TFB1]

In winter I'd bet there would not be any issue at all but once temps were constantly above 60*F, dump a quart of 20W-50 in it...

 

[Zaedock]

Originally Posted By: KCJeep
A well respected member here who now is gone (RIP) ran PP 5w20 in a 4.0 for a test years ago.


Who is it? Gary was the guy who ran the 0W10 in his TJ.

 

[KCJeep]

I couldn't remember the name but I think that is who it was now that you mention it. I don't think I've seen the 0w10 but I did see a UOA in the 4.0 where he did an OCI of PP 5w20. Iron was very typical (and what most 4.0 UOA viewers tend to get focused on) but his al was around 12 ppm IIRC.

I've been paying a lot of attention to the Al due to the skirt issue the later models have.