Ed Hughes

The following information was posted on our local PCA forum. It was copied to there from a British car forum. Take it how you will, but the article raises some interesting facts about the newer API oils, and how they may indeed be taking a step backward. Some of the problems discussed are going to be unique to the valve trains found in older Brit cars and also in break-in of new cars. But, it is interesting reading. It is also interesting to learn a bit about Redline oils, and their performance emphasis.

I looked on their site, and they don't recommend their 15W 50 on engines running sustained oil temps below 225F. For the lower temp engines, they recommend 10W 40. I'm tempted to try these guys next oil change. Has anyone tried them before? One last question: What is typical oil temp in one of our motors?

For the record, I'm not a scientist or expert on any of this. I'm just sharing some information I've run across recently.

hacker-pschorr

Funny this should come up. Friend of mine (builder of the 427 motor in my sig) talked my ear off for a few hours recently. Telling me the story about how synthetic oils were directly related to the failure of high horsepower air cooled VW motors he built. I cannot quote him directly, but it boiled down to synthetic oil not being able to dissipate heat like good old dyno oil. Every air cooled motor he ever tested with synthetic (we are talking 250-500hp VW engines here) showed signs of heat related failure on rocker arms, camshafts, and other parts of the motor. He never saw these issues with dyno oil.

He also went on to explain every cam expert (not the term he used, cannot remember the term) he knows will never run synthetic - again the heat dispersion issue was the #1 reason, among others.

Every high performance 928 engine he has ever run in his car ran dyno oil produced by Lubrication Engineers. Hard to argue with someone who has been designing and building high performance engines with an excellent track record for over 30 years. I have a feeling he will just smile like he does when he reads this.

He did go on to say with modern water cooled engines it’s probably not an issue. He wasn’t going to find out on his car.

I have been very reluctant to post this info from Todd due to possible backlash I could not argue intelligently against. This thread seamed appropriate. So flame away, I'll take notes and ask him for a response next time I see him.

Thank you for posting.

ErnestSw

Ed,
Search the archives for posts by Doug Hillary. He's an Aussie oil expert, a truck fleet and a 928 owner and speaks Scientific (the language).

worf928

Queue Doug.

My personal opinion is that for 99.99% of the applications discussed in this forum any approved-for-928 oil and/or any oil with specs consistent with the owners manual that is changed per schedule will be fine and any differences will be statistically insignificant. A 500hp VW (flat 4 I assume) motor is in the 0.01% wherein the differences are significant.

This reminds me that it's time to change the oil in the fleet.

hacker-pschorr

I agree with your post - just sharing some info for the sake of the discussion. Todd is not one to get caught up in hype about anything. The 500hp motor is on his motorcycle - the N/A engines that also saw the same issue were in the 250hp range. He did say due to being air cooled, oil dissipating heat is much more important than on a water cooled car. None the less, that is what happend.

worf928

Actually, this very issue has been kicked about before:

Reformulated Oil Camshaft Failures

and

Oil Condition Report No 5

worf928

And I don't dispute that, nor am I arguing. Just putting into perspective that the (perhaps) ensuing discussion is about the margins and that we don't need to set our hair on fire.

And, now, I'm reminded that I need to source 27+ quarts of the proper diesel-rated oil for next year - just so that I'm sure that there's enough ZDDP in it. (I still have cases of old ZDDP-laden 20w-50 dino juice for CarChick's 16V Scirocco, assuming I get the thing running again...)

worf928

Thread hijack:

Ok man. That's ****ing insane.

Jim M.

I have an oil temp gauge installed on my GTS. The temp bulb is in the drain plug. My oil temp very closely follows the water temp after both are up to operating tempertures. When I'm really pushing it the oil temp will get about10 deg. F higher than the water, but never above 210-215. I think thats because the water system has a greater cooling capacity.

Jim Mayzurk
93 GTS 5-spd

Ed Hughes

Well the thing that interested me in this, is the fact that there would seem to be a regression here as a byproduct of our "progress". Even some of the oil manufacturers seem to agree. While we don't go screaming in the streets, I think it is safe to say that the fundamental makeup of oils today are a bit different than what Porsche looked at when they wrote the owner's manuals for care built in the 70's, 80's and 90's. We may indeed get to the point where lubricants designed for current production motors (or is it visa-versa?) don't meet the needs of older cars.

Ed Hughes

I was wondering if there was any correlation to the water temp, or if there was some reason that oil would run substantially higher. Based on that, Redline's website recommends that 10W 40 is the viscosity to use. I've not looked ay Mobil's to see if they have specific suggestions based on oil temps. I'm runnig Mobil1 15W 50 now.

worf928

Based upon my quick re-read of the threads I listed above I think that we do need to be vigilant about changing oil standards. Hence my last missive about looking for the diesel-rated oil for next year.

worf928

Follow-up: I just checked The Mobile One site and Mobil 1 15w-50 Extended Performance (the full-synth) meets Doug's personal standard of API SL with a > 4.0 HTHS viscosity.

BC

I'm glad that the castrol HD 30 is still noted as a good break in oil.

hacker-pschorr

http://www.erik27.com/todd/Bike

450ish rwhp dyno verefied - he has made a few mods since then, has yet to revisit the dyno. He said the bike isn't really exciting until 170mph. That is Todd on the drag dyno - he lost his SC belt on the first run, so he was unable to set what I'm sure would have been the fastest time of the day.