hacker-pschorr

1200/1300 ppm for Phosphorus / Zinc isn't too shabby (15w-50).
Even higher if you choose their 20w-50 V-Twin air cooled oil

http://www.mobil.com/USA-English/Mot...duct_Guide.pdf

VR1 returned back 1030 / 1332 here:
https://rennlist.com/forums/911-foru...acing-oil.html

I've seen lower results than both of the above in oil analysis for Royal Purple.

I'm not a fan of Mobil 1 myself, just sharing data. Realistically for your average street driven 928, Mobil 1 is fine.

M758

Thanks Mark!

mark kibort

the worst part of mobil 1 is that it seems to break down at high temps. been a long time since I ran it, but when I did, it turned to "water" at 250F temps.

zoltan944

Nothing made the list formulating under 1400ppm
I see in the thread there was 1 person later that listed lower numbers, but I see others posting higher numbers, also Valvoline posts their data differently:
http://valvoline.com/pdf/VR-1_Racing_Motor_Oil.pdf
there is also the specialty and synthetic stuff i think you get from NAPA.

But anyway, seems everything is tested vs. Brad Penn and Swepco and both of those win in all the tests, so the thread has been updated in its last update to say just buy either of those cause formulations keep changing.

beentherebaby

I also am not a Mobil fan. The only M1 that I know of sold in the U.S. that meets current Euro car maker specs is 0W-40, which is Euro formulation. It's approved by numerous companies including Porsche, M-B, BMW, VW/Audi, etc. I would not use any of the other Mobil oils sold in the U.S. in my vehicles.

http://www.mobiloil.com/USA-English/...l_1_0W-40.aspx

RKD in OKC

I don't trust car makers recommendations. Example: Audi offered free oil changes for 4 years a while back, they used M1 AND did the changes at 15K. When they quit the free oil changes the recommended oil change interval dropped to 7500 miles. Also have heard of several Audi owners that had cars that got the free 4 year stuff suffered valve train failures.

BMW is currently doing the 15K free oil thing on their new cars, will be interesting to see what happens when those cars start getting 50-60k on them.

beentherebaby

A UOA tells you if the oil is still fit for service. Then you don't need to guess. With sales of hundreds of thousands of units annually you are going to always find some engines that have issues and people who have one oil ideology will jump on them. Those who have a different ideology will offer the other 99.4567892341567 % as proof that the OCI is correct.

I use factory spec oils for the application at recommended OCis, a UOA and I never have engine issues.

BTW, with all major Euro car companies initiated CPO sales, they now must warranty them typically to 80-100K so I don't think the car makers price of an oil change has much merit in the grand scheme of things. Since the factory actually durability and wear tests, I'd say they have a pretty good book on what works and why.

dprantl

I really disagree about trusting the manufacturers regarding engine oil choice these days. One of the major factors in new auto production is fuel economy, and a lighter oil is much better in this regard. It is also not so good for wear especially on engines that are run hard. Have you even seen how thin those 0W30 oils are that are recommended these days by manufacturers? They are like water. You can only design engine metal pieces to accept this thin of an oil to a certain point. Plus, after the car is out of warranty, it's in the best interest of the manufacturer to have the car be recycled.

Dan
'91 928GT S/C 475hp/460lb.ft

mark kibort

Me too.

I think, like anything, when there is money involved, the interests are in money, not wear, performance, etc. Just because porsche and mobil oil strike a deal, is that the best oil for the porsche? yeah right! first of all, for general consumption, most any oil will probably work, and work well. I'm sure there are millions of cars that have lasted 100k miles and probably never even had their oil changed, or had Kmart oil in them. With our cars, same thing. however, RACING is an entirely different story and pushes everything to the limit. when I saw that oil pressure light come on with mobil 1 vs regular oil during a DE day, that was enough for me. kendal 1 didnt do that, and neither did redline or Amsoil.

hacker-pschorr

I have a couple cases of Brad Penn in the garage

Other than my SAAB which is using Redling, I'm using Brad Penn in everything else.

beentherebaby

There are many aspects to proper engine lubrication and viscosity is one of them. Thinner viscosity oils flow easier and thus can cool bearings and valves stems etc. better than a heavy viscosity oil. Bearings are hydrodynamically lubricated and only need sufficient film strength to support the relatively mild loads they see in hi-perf engines even when used for track activities. Thicker oils have a function in engines with looser bearing clearances but this is not necessary or desirable in modern engines with tighter clearances which produce reduced wear, better performance and longer lifespan with thinner oils that can flow into these tighter clearances for proper lubrication.

For those who don't know, the German car engineers are very fond of high-speed road and track driving. They conduct a lot of durability testing everyday on the streets around Zufenhausen, the A-Bahn and on the track at Weissach...

The SAE link may prove interesting reading for many enthusiasts.

http://papers.sae.org/2007-01-4133/

hacker-pschorr

From the link:
"These findings could be an enabler for achieving longer drain interval although several other factors must to be considered."

Is there a part 2?

They always seam to do tests like this on fleet vehicles, which makes me believe these cars are run for long intervals at a time with a lot of cruising (versus stop / go).
I would like to see a similar test on a car that sees maybe 5-10 miles per trip (max), especially in winter.

mark kibort

we all know that under high temp,the oil's characteristics do change. if we need 5 bar to provide proper lubrication, then 2-3 bar at 3-4000rpm might be a major issue caused by viscosity breakdown. I only have the emperical testing of what the gage says during race conditions. it would be nice if someone tested the oils at temps of 240 to 260F to see what those differences are.
after what I have seen at the track, and the track record I have had racing the 928 engine for over 15 years, I dont think I would risk my engine with mobil 1, but would have no issues running it in a street car that didnt see the track.

mk

beentherebaby

I'm not a Mobil fan either but I would not hesitate to use the 0W-40 Euro formula approved by Porsche, BMW, Audi, etc. for street or track. More oil pressure does not always equal better.

40 weight oils are going to give similar oil pressure readings at elevated temps based on viscosity. If you were comparing a 0W-20 to a 0W-40 or similar, sure the hot viscosity is typically going to be lower on the 0W-20 weight oil depending on the oil pumps capacity and the leak path in the engine. With a very high capacity oil pump you could have the same or higher hot oil pressure with a lower viscosity oil.

Oil pressure in itself does not define the oil's engine lubrication performance. It's a reference point to insure that you have sufficient oil pressure. More oil pressure is not necessarily better. In fact excessive oil pressure can lead to other issues. As long as you always have the minimum required oil pressure it's all good.

Without controlled testing you do not know if a 0W-40 is better, worse or the same as far as lubricating the engine at high temps, high rpm or on the track. That's why the engineering community uses real world testing that can be duplicated by concerned outside parties. Car maker oil specifications are based on actual engine requirements and the car makers do test at elevated temps. Most car makers require the oil temp to be between 240-260 F for dyno power and durability testing.

mark kibort

I was comparing two idential oil weights. 15-50s

as far as testing goes, its pretty hard to argue with acutal racing testing and results. sure, the engineers can calulate all the millions of variables, or pick out the major ones, put the cars or engines on test stand, but its the REASON that ALL these companies have some interest in racing programs. They need to put their theories and hypothesis to test. What happens under undulating G forces on the track under redline conditions. How does the viscosity or film strength effect bearing protection....etc.? I knew with going with a high quality racing synthetic that was not a marketing machine, my odds would be best with the oils ability to protect, if that could be a problem if it couldnt by a lesser oil. (i.e. redline, Amsoil, etc). in the end, I think what I have done is not that far off what the manufacturers would do. run a car for 8 years, under varied conditions, even pick one that could have an oiling design issue and see what happened. Thats what I did. it wasnt a lucky motor either, its been about 5 motors that have assocaiated with my direction in racing for the last 10 years. no issues, and all motors that have been taken apart have shown no wear issues AND, all oil changes once a season have been sent for oil anyalsis to see if anything unusual would show up. (as well as regular filter cutting. )

Go ahead, stick some 0-20 weight mobil one in your 928 and run it. Just dont get more power than me so you can out qualify and then in the race start, lead me into the first turn.

(disclaimer: I am no oil engineer by any stretch. Just someone that has seen oil pressure drops with the same weight oil at the track by using mobil 1. also, has seen 10 years of success with multiple engines, 2 primary engines still racing today with no issues on Amsoil)