Oil

I know this topic is rarely discussed. However, the current issue of Excellence Magazine (April 2007) addresses aspects of the 0W-40 "oil" topic in a different manner. Both technical experts claim that newer Porsches require the thinner oil to ensure proper VarioCam function. On page 34 a reader asks a question about using 10W-40 oil (for a Boxster) in Florida vs Mobil 0W-40. He is concerned about using the 0W-40 because 10W-30 or 10W-40 is a "more common fill" in Florida (he also asks about break-in). The response from the Excellence technical expert was as follows. "Those who suggest higher viscosity oils usually don't understand the whole problem. Oil in engines is no longer just a lubricant. It is also a coolant for the engine as well as a hydralic control fluid for all of the things like VarioCam Plus, hydraulic lifters, and similar systems. If the oil is too high a viscosity, it can affect the way those circuits operate. The 2001 996 Turbo was the first Porsche to use the VarioCam Plus technology and a friend who works as a dealer technician told me that one of their technicians spend the whole day trying to diagnose a running problem caused by an owner who hadn't trusted Porsches factory fill and thus changed his oil to SAE 20W-50. The heavier oil totally confused the VarioCam plus system and the engine ran poorly. All of these devices have been designed to run with the SAE 0W-40 oils or other oils that Porsche recommends. Use only those oils recommended in your owners manual - SAE 0W-40, SAE 5W-40, or SAE 5W-50. Porsche is so sure about this decision that it came out with a bulletin recommending these oils for all of its older models as well." Now I know that is just one "experts" opinion. However, on page 169 Porsche tech expert Jim Pasha dedicates his entire "Tech Forum" article (6 pages worth) to "Oil". I'm not going to type in all 6 pages of material but I will quote a few short pieces of what Jim reports in his column (he covers a lot of ground in his article). "Why does Porsche specify such a low lower viscosity rating? The answer comes in two parts. First, in a quest for better fuel economy and longer engine life, Porsche engineers use bearing and cylinder-wall clearances far tighter than what they used previously. This creates less internal drag on components, and lighter oil is more compatible with tight tolerances." He also says; "In the latest Porsches, which use 0W-40, the thinner oil is critical to delicatesystems that use motor oil as a hydralic activator. VarioCam Plus uses tiny "shafts" of oil created under high pressure to help the system alter valve timing. It is a trick system but it REQUIRES thin oil to work properly Any of the "heavy oil" proponents care to chime in???

0W-40, 5W-40, 15W-50, Blah, Blah, Blah. I am getting tired of all of this oil talk because I have found a lubricant to use in my 996 which is much sweeter, literally, than any currently P-approved oils. It's Aunt Jemima syrup and IMHO it blows away Mobil 1(AKA Mobil Water). Please note: I use the original formula as I feel the new sugar free version is far too watery and would not provide adequate engine protection, although I'm sure some on this board will dissagree with me. Now granted this "lubricant" is not on Porsche's approved list but I don't care because it is so damn good, tasty even. Here is my take on it. Please keep in mind that I am not an expert in engine lubrication but then that does not stop others here so I am going to have a go at it. 1. Since using Aunt Jemima I have been burning a fair amount of it but I don't care because it smells so damn good when it burns. Hmmmm!!! 2. Since using Aunt Jemima, about 2,000 miles so far, I am happy to report that I have not had an RMS failure. This stuff gums up the seals to the point that nothing could possibly leak from them. I think this stuff will make all of Porsche's RMS issues a thing of the past. 3. I do not hear any valve train noise at start up, even after the car has been sitting for a week or so. In fact, my engine runs so quiet now I can hear the radio perfectly clearly even at 7,000 RPM. Rock on!!! 4. After engine shut down, Aunt Jemima sticks to the engine parts like maple syrup unlike that Mobil 1 water which just runs right off exposing all kinds of bare metal. 5. As far as thermal breakdown is concerned, pancakes are hot arn't they? Case closed. 5. I can't comment with any certainty about its long term engine protection qualities but I will report back with my findings after about 15,000 miles or so. When I do my next oil change I will put the used oil on my pancakes to see if the syrup, I mean oil, has a metallic taste to it. Who needs a laboratory oil analysis, not me. Flame away if you wish but I truly believe the Porsche engineers will vindicate me by eventually adding Aunt Jemima to their APPROVED(NOT RECOMMENDED) list.

No of that synthetic crap for me. I buy real maple syrup from Trader Joe's.

DreamCarrera, you may be on to something there!!

Read the Excellence article tonight also, but I do have to say my oil pressure is the lowest it ever has been with 0-40. The "nitrous boost" from the vario is a lot smoother or less abrupt though, I believe the 0-40 is better for the vario system.

Oh crap, Ray! You could have given me a "heads up" that you were going to start Oil War XXIII ! Now I'm scrambling to get the popcorn machine warmed up and the drinks iced down!

OK, I'm all set! The popcorn is hot and the drinks are cold! We're good to go!

Scrambling....Huummm Scrambled eggs and pancakes? You may be on to something there Tim DreamCarrera...very nice post and thoughtfully put together

Eric makes a good point, but remember too that most of the stuff at Trader Joe's is organic, and I think the car would prefer that. Does anyone know if there is a viscocity difference between Vermont maple syrup and the Canadian varieties? Michael

Tim, you should have all that ready to go for Sunday anyways. I'm just trying to provide a little pre-gsme warmup. Go Bears!!

In my old 996 (2001, 3.4L, so variocam not plus) as the miles wore on, pressures got lower and lower... eventually to ~ 1 bar in warm-hot weather (call it >75F)... At 75K, my indy switched me to 15w50, citing 1) leaks less, 2) age of engine 3) better pressure. After 15w50 fill was added my pressures returned to normal... 1.5 bar at idle, and ~4.1 bar at >4K RPM... Also noticed engine ran a little smoother... albeit may be my imagination. So the question is... does it make sense to move to a heavier oil as mileage increases?

Yup, same here. With M 0-40 < 1 bar at idle. Actually had lifter noise that went away with increased idle (and increased oil pressure). After switching to 15w50, 1.5 bar at idle and no more lifter noises.

Who makes the 15w-50 you guys are using? Is it on an approved Porsche list so those of us with warranties can use it? Sounds like a good idea to go heavier in the summer to me but I only feel comfortable with an approved oil.

In my new 03, with 12K miles, oil pressure @ idle is ~1.5 to 2 bar with 0w40... will continue to run 0w40 until I get in the 1 bar area again. (should be ~60K miles)

I think the Excellence article re: oil weight,seems to make sense relative to the internal workings of varo-cam,etc. So,now there are 2 concerns:engine lubrication,and internal hydraulic functions. On newer engines anyway,it may be prudent to stick to the 0-40 ,5-50.

I don't look at the oil or temp gauges...one less thing to worry about And, like I tell my race mechanic...I don't have time to stare and no Fing gauges, I'm racing out there, if you didn't notice

"Best lubricant for any Porsche" -

What change interval do you follow with that stuff.....

Ray, great post! I read this yesteday myself and the first thought that came to mind was how this would go over on Rennlist! Waiting for the "other side" posts to come in

Don't get the water-based one. It dries up too quick and might cause the shaft to scratch the cylinder walls, causing MAJOR detonation.

Isn't there a Knocker sensor for pre-detonation?

The "VarioCam" info adds a new twist to the topic. I'm guessing the "other side" doesn't have an answer. Don't get me wrong, I am not of the opinion that "stock" Porsche equipment is the only/best solution (I have some non stock equipment on both of my Porsches). However, I have not seen any credible reason to go against Porsche recommendations when it comes to oil.

It should help a little, depending on how much it advances or RETARDS the timing.

I live in South Texas and the 0W-40 oil pressure at idle has been low as 0.6 bar, I am going back to 15W-50.

Oh dear God, here we go again!

I am not starting anything as this has been beatin' to death but this is the first time I used 0W-40 and my oil pressure has been very low. I am not taking any sides on this as 0W-40 is supposed to be 40 weight and 15W-50 is supposed to be 50 weight oil, of course there is a viscosity difference, just one I do not like. Thats all.

What you like and what your motor and variocam like are apparently 2 different things

Can you elaborate Dell? In all my years training as a mechanic and being a mechanic (come on degree), low oil pressure is a bad thing. Obviously 0.6 bar is like 8 PSI. That is really low no matter what RPM to me. I agree with the Variocam wroking better, I have noticed a great difference in transition but my main bearings and rod bearings riding on 8 PSI seems way too low. Maybe I dont know something about Porshes that someone could enlighten me on, I am open-minded. By the way Dell, I am on my second stats class, seems pretty interesting.

Did you read the first post in this thread? My suggestion is to go pick up a copy of this months Excellence and read up. The article is quite lengthy and does a nice job of explaining quite a bit.

I have it and read some of it

Oops, I should have read on. Sorry

Sounds good as long as you're basing you decision on such solid reasoning. Good luck with the thick stuff.

Tippy, your question might be an excellent one to ask the techs at Excellence Magazine. If you are indeed seeing radically different oil pressure readings with 0W-40 vs. 15W-50 perhaps you should send a query to Excellence and see what they think the real issue may be. It will only cost you the price of a stamp to ask. Good luck!!

Now there is some good advice. I'd stick with 0-40 if I didn't have such low pressure readings with it at idle (and tapping noise).

Oil pressure is not an indication of a lubricants success or failure to do the job. A less viscous fluid will naturally cause less "backup" in an oiling system and will register less pressure. That means flow is good. Heat is wicked away by flow and volume, not viscosity. Obviously, abnormally low or high pressure readings indicate a problem. But using a higher viscosity oil just to increase oil pressure is not advisable.

Nicely put Brant

Thanks Dell, wonder where the "other side" is today? Running around buying up all the Excellence magazines and burning them I suppose.

Probably busy buying stock in Mobil before the market closed!

Almost like finding out your daughter posed nude in a mag

Funny!

I agree with everything you said except for one point. What about older motors? Obviously the tolerances have "loosened" since new and running say a 10 weight higher viscocity probably would be better for the engine, no? This in turn would raise the oil pressure closer to the orignal, just a thought and many around the world do this. To add to the heat dissipation point, a fluid engineer came to my company and explained that the oil of jet engines acted as a heat dissipator, not as a lubricant, knocked the shocks right off the other engineers of my company. Being that jet engines are air-cooled, this is needed but the fact our cars are water-cooled, the heat dissipation through the oil is not as big of an issue, possibly?

Hi Tippy, If an engine is that loosened chances are that while thicker oil will increase pressure, there are other issues that need to be addressed before we depend on a thicker oil to bail us out of longer term trouble. It is definitely true that a thicker oil can be used to mask rod bearing problems, but eventually it will need to be repaired properly. As far as heat transfer, an oils job is to lubricrate as well as dissipate heat. The oil in a water cooled engine wicks heat away from the internal components to the engine block where the coolant flowing through carries that heat to the radiator. So, in effect, it is still a very important role in a water cooled car.

Dell, you really crack me up sometimes!!

Hello Grant, True, from a race motor standpoint. Daily beaters and garden variety motors not so critical, correct? Hence, oil coolers only on high RPM/performance cars. Not trying to contradict but it is relative to what situation the motor is operating in; high performance or basic transportation.

It is realtive to the situation, but the basic principle of oil transfering heat away from engine components and to the radiator fluid would still apply. That is why there are different oils and different additives for the oils depending on the usage.

Right on, isnt it funny that Porsche just didnt put the oil type on the oil filler cap.

They did not do that so that this forum would have plenty to discuss

They have 46 oils on the current list. They may not all fit.

I buy one each of the 46 listed and mix well. At oil change time I extract what I need and fill the car. Bases covered