Originally Posted By: userfriendly
You cannot connect the dots as you wish, then adjust engine oil viscosity to suit your logical fallacy.
Light truck Diesels are putting out 400 hp @ 3,500 RPM with 6.5 liter engines and 10L oil sumps.
You are comparing that, to a 13L engine producing 550 hp @ 2,200 RPM and a 40L sump?
This has nothing to do with UOA's, history or comfort zones.
There is nothing stopping someone with a 3500 fully loaded pulling a 5 ton trailer,
from going up a mountain pass with their foot on the floor all the way.
Now consider a tuned light truck Diesels @ 550 hp and the same 10L sump.
But this time empty, going up the same mountain pass blowing by everybody @ 100 mph.
Neither examples are "jerking 80,000 lbs", but they are not going up that hill with 10w30.
But my small ag tractor with a smaller engine than the Dmax also gets a 10w30 and works it hard on some pretty hot days. Same deal. Works great. I get less shearing from 10w30 HDEO in all my applications than I ever got with a XXw40.
And while it is true that the older engines like the Detroit 60 are getting their max HP at 2100, they also are getting max torque at 1200. Many HD diesels in commercial trucks are doing all their work between 1300 and 1500 RPM. That is substantially lower than the Dmax is doing stuff and that can really stress components. GM with it's pickup Dmax is about the only holdout that hasn't moved to a XXw30 as both a factory fill and recommended vis nowadays.
You cannot connect the dots as you wish, then adjust engine oil viscosity to suit your logical fallacy.
Light truck Diesels are putting out 400 hp @ 3,500 RPM with 6.5 liter engines and 10L oil sumps.
You are comparing that, to a 13L engine producing 550 hp @ 2,200 RPM and a 40L sump?
This has nothing to do with UOA's, history or comfort zones.
There is nothing stopping someone with a 3500 fully loaded pulling a 5 ton trailer,
from going up a mountain pass with their foot on the floor all the way.
Now consider a tuned light truck Diesels @ 550 hp and the same 10L sump.
But this time empty, going up the same mountain pass blowing by everybody @ 100 mph.
Neither examples are "jerking 80,000 lbs", but they are not going up that hill with 10w30.
But my small ag tractor with a smaller engine than the Dmax also gets a 10w30 and works it hard on some pretty hot days. Same deal. Works great. I get less shearing from 10w30 HDEO in all my applications than I ever got with a XXw40.
And while it is true that the older engines like the Detroit 60 are getting their max HP at 2100, they also are getting max torque at 1200. Many HD diesels in commercial trucks are doing all their work between 1300 and 1500 RPM. That is substantially lower than the Dmax is doing stuff and that can really stress components. GM with it's pickup Dmax is about the only holdout that hasn't moved to a XXw30 as both a factory fill and recommended vis nowadays.