jansan946

Years and years ago, before porschelist became rennlist, an oil thread developed about whether or not 15W-50 Mobile 1 was worth the premium cost compared to dino oil. Steve Weiner (and I hope that my memory hasn't totally failed, Steve) commented that it was definitely worth it and went on to relate a recent experience. As I recall, he described a track incident with a customer's 911 whose oil pressure went to zero a few laps before the race ended. The motor was subsequently torn-down and no damage was observed. I was using 15W-50 Mobil 1 then and I'm still using it now.

So Steve's correct: "Its always best to choose a good product and then stick with it..." and so is Mike Schneider: "For the life of the (993) coupe Mobil 1 synthetic oil has been used.

fsa

Brad Penn is available. Jeff Gamroth at Rothsport uses it routinely, at least in non-track cars like mine. Steve above referenced it in an earlier post.
Suggest you contact Earle, parts manager at Rothsport for a source. He's very knowledgeable and helpful.
Fred, Portland

Steve Weiner-Rennsport Systems

Brad-Penn is an excellent product and we use as well as recommend this as the best non-synthetic you can get.

Like ALL racing oils, one cannot leave it in service for 5K+ miles without consequences since all such oils contain fewer detergents than non-racing oils do. Like everything in this world, its all a tradeoff and IMHO, a good one.

If someone has a sludge problem, thats rooted in human factors,...i.e., maintenance issues.

Gbos1

Just responded...........

bpu699

Glad to hear that... Sill being recommended for turbos too? Used on the track?

With racing oils, is there a time limit to how long it can stay in your motor?

If you do 3 tracks weekends, and then it sits 6-7 months, is that an issue?

Any thoughts on VR-1 vs Brad penn?

Bill Verburg

Most will agree that there are mostly excellent oils available today, the choice for our older cars comes down to the single question

Does this oil contain between 1100/1200 to 1600/1700 ppm P/Zn that is needed along w/ a matching detergent package for long life on parts like cams?

Once again the cam wear issue became a problem ~2004 when ZDDP levels were dropped to 1000 then 800 and later 600ppm in the ILSAC GH4 & 5 oils.

• Flat-tappet cam failures started with the reduction of ZDDP < 1000 PPM.
• Based on this, 1000 PPM ZDDP is the minimum required level.
• Levels of 1200-1400 ppm ZDDP may be required for more extreme cams. What level defines too much ZDDP is unclear, but for street use more than around 1400 PPM is likely not appropriate.
• Oil change intervals should be no more than ~3,000 miles with dino oil, ~6,000 with synthetic.
• Any oil marked API SM/SN, ILSAC GF-4/5 or ILSAC CJ-5 in grades SAE 0W-20, SAE 5W-20, SAE 0W-30, SAE 5W-30 and SAE 10W-30 cannot have sufficient ZDDP.

If you choose to take anyone's word that their oil is great, the fine go for it.

Being a skeptic I choose to only believe published data. There are several oil manufacturers that publish the info
among them
Mobil
Brad Penn
Gibbs
I'm sure that there are others, but I also like a widely available oil and those fit the bill.

For the era when 964/993 were built
M1 API SH 15w-50 circa '93-96 1095ppm P, 1427ppm Zn

wt from the owners manual for summer use 15w-50 or 15w-40


lastly i'll just point out that Porsche engineers recommended M1 0w-40 for our cars for several years, not only is the weight out of spec but the 1000/1100 ppm P/Zn package is dangerously low. These implies that they do things for their own reasons which may or may not be aligned w/ ours.

jscott82

Just to throw more variables into the pot.. Ill add..

I had the opportunity over the winter to have dinner with one of the top air cooled engine builders and asked the question... For my specific case: stock 993 motor, no internal modifications, no cat, used exclusively for DE/Racing.. He unequivocally recommended Royal Purple XPR...

I always though RP was for the poser "street rod" crowd... Was surprised by the recommendation, but i'm trying it this year...

Bill Verburg

Sure many builders have their own favorite, like I said, there are many fine and appropriate oils out there. Of the builders in NE that I have spoken w/ M1 is the most common, w/ 1 Motul and 1 Cenpeco.

If any one is satisfied w/ word of mouth or manufacturers claims, that's fine, but I put far more credence from someone that is willing to publish specific oil specs.

These oil controversies have been raging ever since I was a kid many, many moons ago. first it was straight vs multi-vis oil, then it was dino vs synthetic. Back in the late '80s there were rumors that major builders were refusing to use Castrol 20w-50 dino any longer because of issues. I know one guy(a heart surgeon) that bought a '93 964 new always used what the dealer recommended at the factory recommended intervals, they put Castrol 5w-50 in at some point, the motor was trashed by the next oil change(~3-4000mi of commuting ~120mi a day) was it the oils fault? Who knows. I did speak w/ a Castrol engineer at one point he would only admit that there was no Castrol product sold in N.A. or Australia w/ more than 1000ppm ZDDP, Do they have such in Europe? again I dunno.

Bottom line I believe and will buy from manufacturer's that publish specifics, have otherwise good reps, and are available at a decent price. I don't mind paying for things but is a$11/gt really better than a $4/gt oil?

On my shelf are M1 & Brad Penn, but I rely more on the M1 because I have to buy the BP 4-6 cases at a time then store them until needed. Are there Motul, Gibbs Valvoline products equally good? probably but they don't sell that around here and if they di the price would likely be an issue. Just compare M! 15w-50 @ ~44/qt to M1 Vtwin @ ~$10/qt. Do you need it? Are you getting 2.5x more value and protection? I don't think so since the M1 is right on the target for what our cars used and were designed around from day 1 and which subsequent experiece has shown to be fine.

Porsche used to be great at publishing specs so that people could make informed decisions, not so much any more.
examples are the oil and the new Porsche/Bilstein shocks. As w/ the oil they take a great shock and put their name on it at double the price and make all sorts of extravagant claims w/o any documentation. I have Bilsteins on both of my cars and know the details right down to valving for both. Before I bought Porsche/Bilstein or Porsche oil I would want to know the details, which sadly have not been available.

and lets not forget the weight issue, out cars were designed around API SH oil 15w-50 or 15w-40 for summer use, even w/ these weights I have experienced lifter pump up issues on cold starts, I shudder to think what a 10w-60 would be like. But again it's your car and your decision.

One more point that is rarely mentioned, there are other parameters that affect the efficacy of oil. Like brake pads lubricity is dependent on temperature, most oils work best above ~185F and below ~240F, Cold starts are hell on a motor as is running too hot. Cam design also affects oil needs, a full race cam will have much higher loads than a normal street smog cam.