Porschetech3

Dealers are not "required" to use Mobil 1 or Porsche Classic , but must use an A40 approved oil for warranty purposes., they do have discretion over what brand to use for bulk oil. The dealership I worked for kept Mobil 1 0w-40 5w-50 A40 and 5w-30 C30 as well as "Porsche Classic Oils" on hand in quart bottles. The "bulk oil" brand changed a few times as the oils would loose the approval if not kept up to date. I remember the bulk oil being Kendall/Phillips66 A40 and Castrol Syntech A40 at some point, and would be used in most cars unless a special request was made. I have no idea what they use now, but I know all Porsche Driving School Cars get Mobil 1 5w-50 exclusively

Charles Navarro

It's good to have that data point that they all ran N spec tires. It's long been the thought that if you ran an N spec tire that it was damn near impossible to have oil starvation.

On another post you mentioned they used 5w50 M1, which that would help bump up the HTHS viscosity and further provide an added level of protection for the stock and unmodified engine.

Thanks for sharing.

Porschetech3

Hi Charles, the information about the N spec tires was reported by Porsche. The m96 996 was designed to run N spec tires and not racing tires or R compound. That means the oiling system was just barely good enough to keep from oil starving with N spec tires, but something changes with age/miles on these engines that some people report oil pressure drops on the track even with street tires.

I have a few theories on why this happens on cars with some age/miles and not on new cars such as the fleet of Porsche Driving School cars that I was in charge of maintenance, they didn't even have deep oil sumps, and were on track daily at Barbers Track..But I'm not in a position to test these theories, all I can do is implement them on my cars, but that's just one data point.

The problem is simple. but the cause/solution is complicated. The simple problem of oil starvation is just two fold, either too much oil leaving the sump fast, or too much oil returning slow. But 9+ quarts of oil should be enough to do the job.

I think that the increase in blow-by in cars with age/mileage compared to new cars is responsible for the difference. The theories I have for the solutions to handle that (short of a refresh/rebuild/reconstruction), are still just that, theories. I'm not able or have the means to test them.

pdxmotorhead

Makes sense,, I've seen wet sump corvettes lunch engines shortly after they upgrade to the comp suspension and Slicks..
Accusump is mandatory in that scenario...

jgiannone

Once again, I'll probably end up regretting this, but my experience has been different. My car has been highly modified; much lighter than stock, much lower than stock, and much wider than stock, and has run on both Yokohama slicks and Hoosier A's for years now. From the G force data in the car, it runs over 1 G almost all the time into and out of corners, and in some corners like Turn One at Watkins Glen, I've seen spikes up to 1.6 G's, and have had no oil starvation issues (otherwise, the engine would not have survived the 26,000 race miles). My only answer again is the deep sump, filled to the top line, and the oil warmed before hand. Some of the "stock" classes in PCA Club Racing have dwindled in attendance in recent years, but I've seen many 996 and 997 cars run in H and I stock for years and not have oiling issues. I've also seen rebuilt engines with accusumps that eat themselves. To reiterate, my car is an 03, not an earlier car, so people more knowledgable than me can speak to the upgrades done between 99 and 03. BTW, Kelly Moss that runs the majority of 997 and 991 Cups in IMSA, PCA and otherwise, uses Mobil 1 0-40 Euro exclusively in their customer cars, which happens to be the factory fill on Cups. My opinion (not fact) is that Porsche would not risk their reputation for solely an advantageous marketing partnership. Must my 2 cents.

Flat6 Innovations

In my circles I've had a ton of people attend my classes and this topic comes up. The general consensus with the Cup engines and etc is those prepping the cars don't want to get caught up in a situation where a finger gets pointed at them for something going wrong, because they use their own judgment. They just do what they are told, so they can throw their hands up in the air and say "sorry, not my problem" if something happens.

I haven't sent an engine to the track with M1 in the sump/ oil tank since 2002, and have no intention of doing so, unless its to gather data, and comparatives.

Most every car comes here filled with M1, none of them leave with it. They will never use it again. That's my 2 cents.

Porschetech3

The oiling system on the Cup cars is of cousre the "drysump" race design and can handle G forces no problem.

The 996.2 head design has a better oil return flow to the scavenge pump than the 996.1 head.

On the 996.1 the rare (not available in the US) x51 had a dual stage oil scavenge pump on bank 2 to help with oil return on high G force. the 996.2 X51 did not need this extra scavenge pump as the head was redesigned with a better oil return to the scavenge pump.

The 996.1 is the most likely to experience pressure drops at the track, some people have even reported pressure drops on high G force turns on the street with street tires and a deep sump on cars with some age/miles. I think a lot of improvement can be done on the oil system. I have a lot of ideas to improve the oiling of the 996.1 that some of the top engine builders are probably using to keep these from spinning a bearing.

Like I mentioned above, all the Porsche Sport Driving School Cars are completely stock, no deep sumps, and all run Mobil 1 5w-50 exclusively on track daily for years, and change oil once a year.

Ahmet

I have posted about this in the past, but to re-iterate, I have owned 7 996s, 3 early and 4 late (1 C4S). One of them had an X51 pan. I have also driven 3 other 996s, 2 early and 1 late on track and instructed/observed countless others. Even though I have never experienced a failure (over 100,000 miles of mixed street and track use with different tire and suspension set ups), every single one of them has oil pressure visibly drop on long right turns as per the factory gauge, sometimes down to 1.5-2 bar. I started taking VIR's turn 1 in 3rd gear (~3000 rpm or so), which results in a steady pressure with no perceptible drop. I have also owned and tracked turbos and a GT3, which show absolutely no oil pressure drop in any turn including with slicks. This always made me take notice, but I have not done anything beyond an X51 baffle which has had limited observable benefit.

Of course I used to track/race BMWs which didn't have a factory oil pressure gauge, so who knows what the pressure was doing. Those cars did starve for fuel with under half a tank under the same conditions... and go through wheel bearings... and ball joints, and shock mounts, and water pumps, and radiators and and and... In comparison, the 996 has been a great trade, and they're more fun

pdxmotorhead

My E46 330XI with a factory Msport package (Factory delivery optioned...) ,, Was a ton of fun,, it didn't have the e-ticket ride power my C4 has..
But that car could hang HARD in a turn..

My 69 911T wasn't as power fast as the 996,, but I loved the dry sump air cooled engine,,
and that car was just a go cart, in may ways it was more fun than the 996,,
It did have Magnesium Carerra Front calipers.. and 15x8 wheels on all 4 corners..
Ran a square setup with goodyear's...

I really miss the feel of a all manual car,, with 8 fuses in the fuse box..

996.2

I'm pretty sure what Porsche really cares about is negative publicity, and that they know very well all failure modes and mitigation measures of M96 engines, so if we find out what oil they are putting in 996s we can get valuable information from them.

Our first oil change was at the dealer. We had no idea additives and viscosity and base stock etc could be important to engine longevity, so didn't think to ask what they put in our car. As you mention they have bottles and bulk so if I ask them now not confident will get accurate information, they didn't seem to care about our older model didn't even wash it.

Porschetech3

A lot of dealers don't use bulk oil, they just use Mobil 1 in bottles, but if they use bulk, you can be sure it's A40 Porsche approved.

Porsche probably uses Mobil for factory fill because Mobil has deep pockets, If they screw up a tanker full of oil for the Factory assembly plant, Porsche will be digging into those pockets..

pdxmotorhead

My 69T still had the "Use SHELL oil only" sticker in the engine bay when I sold it.. LOL

jgiannone

One of the points I was trying to make was that the brand of oil is far less important than the change interval for its intended use, and its temperature when you lean on the engine.

808Bill

What are the "go to" oils today?
DT40 is just to expensive (for me) to ship to Hawaii knowing it's going to get dumped in 6 months (2000 Miles)

strathconaman

Rennlist + engine thread = oil thread

I am willing to shell out my money for DT40, I just wish there was more data. I can't find any hard data or independent testing on DT40. For all I know it is 50% maple syrup.