4WD
$50 site donor 2024
C’mon man … the Lucas plastic gear gizmo crushes that - plus you run your own test
SAE Paper on Engine Wear with 20 wt. oil
- Thread starter Al
- Start date
- Status
I’ve tried to find (internet) my particular manual (2017 GMC 5.3) exclusive to other countries but to no avail. Any suggestions as to where this exact manual to include “range” of motor oil weights may be found? I see this discussion here time and again regarding the manufacturer’s approval of heavier oil in other countries. Personally I would like to see that in writing from GM.
Any suggestions, directions, and/or criticisms are appreciated.
I live in “NASCAR Country” 5 miles from CLT Motor Speedway. Many race teams headquartered here. The only discussions regarding the use of 20 weight in race motors were for qualifying laps.
The link didn’t seem to work but here is the website if anyone has time to search for alleged SPE papers.
Last edited:
The correlation between wear and film thickness (HT/HS) is well established. The question really is what means of harm is there in using an oil with a somewhat higher HT/HS? There isn’t any. Oil grades are recommendations not requirements and as long as the MOFT is not so low as to cause excessive wear then an engine will operate on a large range of grades. If that were not the case then every single engine operating at a viscosity greater than that at normal operating temperature would be destroyed. No engine requires a low HT/HS oil. It may be designed my tolerate such an oil but it is not required.
Thanks for this explanation although I’ll press on with my original question…
Is there evidence supporting the use of heavier oils in other countries specifically with late model GM 5.3?
Why not?
Not sure I understand the Why not but the topic of heavier oils used listed in owners manuals for cars/trucks in other countries continues to come up. Just wondering if someone here can actually provide a manual (screenshot or photo) with this info specific to the late model GM 5.3 V8?
Here is a lead. The Silverado ZR2 will be available in Oz and NZ. I believe GM recommends 0w20. Maybe our brothers in Oz can track down the owners manual.
Last edited:
And here is what GM wants for the 2023 Silverado in the USA.
That’s what my owners manual states as well. No variations in terms of weights. I’ve used 0w20 for 75k and have not had any problems with oil usage, noise, or low oil pressures. Have towed a 4K lb. boat for 200 miles in the heat with no problems. The AFM is still as built fro the factory. No alterations. Just wondering how folks know what a GM manual recommends that’s produced for GM trucks used in other countries?
You do know why they state that, right? And why it is stated exactly the way it is? The truth is that oil grades listed in the manual are recommendations but there is a very specific reason the manual is worded the way it is
And a hint is that it’s not technical.
Look for an australian manual, best chance of that engine being sold there.
Big honking V8 are far and few between in Europe, especially in USA cars. I'd say they are mostly private imports.
In fact, I'm not sure GM even has a presence in Europe anymore after selling Opel and the withdrawl of Daewoo/Chevrolet.
Evidently you never spent time in their garage or pits.
You are correct. There are already many hard use Japanese fleet vehicles doing that using 16W.
OVERKILL
$100 Site Donor 2021
And that's what the OEM's are counting on. As I said, it's something that won't matter to Joe Average, but the CAFE numbers matter to the OEM, so it's a win-win for them. Just because something is measurable doesn't mean it's significant, ergo, just because going thinner may accelerate wear in some areas doesn't mean that this will be of consequence to the useful life of the equipment, particularly if the tendency is for it to be taken out of service by other events/conditions.
The problem is when somebody drags out the "pile of failed engines" fallacy rather than acknowledging the nuance of the above.
Are you not familiar with the OP's inclination to run super thin oils in Super Cars that call for grades like 10W-60? If not, then I understand why you might be inclined to think that preposterous.
Long time ago I posted on here about living in Illinois from 1969-1973 when I was in grad school. It got pretty darn cold there in the winter and almost all the folks I knew that had pickups ran straight 20 weight oil in them. Never heard of a lube or engine problem. So using these lower viscosity oils 50 some years ago did not seem to be detrimental to the engines it was used in. Long before polymer coated bearings.
Please, let's have an academic and respectful discussion here.
The one single compelling colossal metric that convinced me to be in the "thick crowd" is the HTHS wear graph which shows running any oil lower than HTHS 2.6 (0W-20) results in exponentially higher engine wear.
Please let us know why the ultra thin crowd ignores this metric and why you feel this metric is not important.
If you are concerned about engine wear at engine startup, 0W-8, 0W-16, 0W-20, 0W-30, and 0W-40 all have the same thin viscosity at engine startup. So the focus of this discussion should be engine wear at temperatures higher than 100C (212F) and why a thin oil is beneficial during high temperature, high RPM, high sheer, heavy load conditions. Typically the coolant temperature is around 100C in most cars during normal operation, but the bearing temperatures can go much higher (as high as 150C). In this scenario, all oil becomes thinner due to the heat, and there is a danger of metal on metal contact when the film thickness gets too thin. So that is why using a HTHS oil >= 3.2 is beneficial, and 3.5 being optimal. This gives a cushion of protection when the oil sheers to the next lowest grade as the oil ages during an oil change interval.
Last edited:
Yes but the SAE grade designations have changed many times since then, and besides that was a grade recommended only for cold weather. I am quite certain the manufacturer did not recommend a 20-grade for hot weather operation.
Yes things have changed in 50 years but the underlying physics has not. Polymer coated bearings notwithstanding you still need an adequate MOFT to keep parts separated otherwise bad things will still happen.
- Status
