Motor oil from an engineer who does his own analys

74Wind wrote: Good point. On reflection, not sure they actually qualify under the definition of high-performance, but as I don't recall regularly flooring the F150's I have had to high RPM's particularly under such sporadic marine use, they definitely qualify as high workload.

And Rotella is widely used on diesel semi truck engines, not changed for over 50,000 miles. You wouldn't consider that severe service?

Read the data sheet... That won't lie.

74Wind wrote: I have also been using Rotella with seemingly no ill effect, and based on many many prior threads, a common choice for many others as well. Paragraph #112,342,1 says not best for use in high-performance engines, however, would one really call this 41 year old engine of mine, also the standard F150 engine for decades, a high-performance engine?

Absolutely not high performance either in the general sense of HP per cubic inch or in the context of the article which is focused on how radical the cam is. Factory marine cams in these old low output engines (351w and 454, not sure about the earlier old technology engines) are hydraulic, low lift, with gentle ramps, low valve spring pressures, and low revving. Those are the factors most relevant for how this test measures oil film strength.

It makes little difference to the cam if there's no load or immense load on the flywheel. The cam goes round and round with the same spring pressures exerting the same psi on the cam lobe. The important difference would be oil temperature relative to thermal breakdown of the oil where it presumably begins losing film strength. High RPM and load will drive up oil temperature potentially reducing film strength.

Rotella (72,022 psi) or Rotella T6 (67,804 psi) have relatively low film strength, which works fine for a mild cam as the psi exerted on the cam lobe by the lifter is low as compared to an aggressive hydraulic cam or a solid cam. Suggest reading the diesel oil section of the article for more details on diesel engine oil requirements. I suspect my higher RPM big block with a high spring pressure, high lift, fast ramp rate cam requires more from the oil than my lower RPM diesel with low lift, low spring pressure, slow ramp rate cam that also has an oil cooler.

Good point. On reflection, not sure they actually qualify under the definition of high-performance, but as I don't recall regularly flooring the F150's I have had to high RPM's particularly under such sporadic marine use, they definitely qualify as high workload.

A bit disappointed with the severe lack of detail in the attached report. How can you summarize such an elaborate subject into just the 10,541 paragraphs listed?

I have also been using Rotella with seemingly no ill effect, and based on many many prior threads, a common choice for many others as well. Paragraph #112,342,1 says not best for use in high-performance engines, however, would one really call this 41 year old engine of mine, also the standard F150 engine for decades, a high-performance engine?

shierh wrote: My engine builder says use Rotella for this reason.

Steve,
And what is the reason?

The guys sure likes to toot his horn!

VR1 rated good, so no worries there.

Some interesting snippets:

"All oil bottles involved in the testing were thoroughly shaken before the samples were taken. This ensured that all the additive package components were distributed uniformly throughout all the oil in the bottle, and not settled to the bottom."

So we should shake our engines because the additives settle out? Maybe just drive trailer on a rough road to the ramp?


"found a wiped cam lobe and ruined lifter. There were metal particles throughout the entire engine, causing devastation which had damaged the rod and main bearings, the oil pump, and the crankshaft, thus requiring another very costly and time consuming total rebuild"

This guy must have had a fram filter. How else did metal particles get into the bearings?

Peter,
Here's a direct link to the article

Interesting conclusion that the ZDDP is a myth. He did do some testing but unless I missed it, the testing was all in the lab. I've seen real life examples of cam lobes worn down almost to round after the owner switched to modern synthetics thinking they were better. I also was in the metal stamping field from 1991 to 2012. During that time, we utilized 3 oil suppliers and all of them said there wasn't a substitute for ZDDP. I think I'll stick with the ZDDP oils for my vintage engines. I sure don't need any problems!