Kevin

Mobil 1 5W40 Diesel Truck which is the Heavy Duty Delvac Synthetic in the heavy industrial side is a very good oil. I am running 5W50 Mobil 1 that is getting tough to find. Motul 300V 5W50 is also a good choice. For guys that are tracking the car, or living in hotter regions the 5W's are oils to really consider.

For the 996TT do NOT run a 15W50 or higher weight.

Chuck Jones

I've bought the Mobil 1 5W-50 also and have referred a number of folks to my source....but Slant 911, you just switched recently...and I believe you live in the hot climate of Nevada. After a couple of weeks, how are you finding the results you get from switching from the 0-40 to the 5-50? For those of us who live in the hot summer areas coupled with the mild winters (by mild I mean temps never go lower than 20 above), there's really not much need for something as thin as the 0-40. I do NOT want to resurrect an oil discussion...just looking for Slant911's assessment of his use of the 5W-50 after about a month...

Kevin: I didn't realize you were using it regularly.

Oak

my engines revs much quicker and more freely w/ 0-40. very noticeable.

slant911

Chuck, Thanks again for the hook-up on the oil.

Well after only about a month I've only noticed that the valvetrain is quieter. Other than that nothing really different. I will be curious to see how oil consumption might be effected over the long run. Too early to tell on that already though. I'll keep you posted. We are getting an early summer here hitting 100 today already and have been in the high 90's for the past week or so.

Chuck Jones

I wouldn't expect much change in terms of anything but consumption over a period of time, especially when it really gets hot. I would expect it to run the same....just maybe a little quieter like you already noticed....but not much else. I'm going to be changing out mine in another 1K miles and take on the summer with the higher viscosity.

kezcapt

I know this has the potential to be incendiary but... The way I understand it the reason for the switch to "0" designated oils was due to Variable Valve Timing (VVT) technologies incorporated into 996 and later engines (e.g. VarioCam etc.). In these engines the oil serves as both lubrication and hydraulic fluid for the valve train. Unlike earlier engines you have the potential to get more than just a little ticking with oil that is too thick but the actuation of timing AND duration has the potential to be affected as well. When combined with manufacturers recommendations against long warmup times in NORMAL use the 0-W40 oils should make the engine last longer and run better, initially, until normal operating temperatures are achieved. With that said, if you are going to track the car, then you are in a different operating regime and your oil needs likely will change. Obviously, the engineers at Weissach have put a good deal of thought into the matter and their engineering should be factored into your thinking. As an aside, I live in a hot climate so I considered a heavier oil but then I got a look at some 996tt valve trains and their very tiny orifices for VVT. It was immediately obvious why my car runs better at startup with the thinner oil. I'm not trying to oppose anyone's viewpoint but give you some of my experience. Racing is a different animal entirely and as we all know, what is good for the track is rarely optimal for the street and vice versa.

Land Jet

Chuck, can you give me your source for 5W50 Mobil 1? I can't find it in these parts.

slant911

kezcapt,

The 5W50 oil is Porsche approved as I understand it. I've gone to the thicker oil simply because I never see temps below 30 degrees in the dead of winter. However, I do see many temps around 110-115 in the summer (which by the way lasts for about 5 months). That kind of temperature in my mind is about equal to tracking the car everyday.

adam_

I just changed to the M1 5w50 (thanks to Chuck for sourcing it!)

I'll report back- so far only 12 miles on this fill, but car definitely feels faster, revs quicker, runs quieter, better gas mileage ...oh, and lower consumption.

Er, yeah...

Summer temps will range from 60F to 110F for the next 6 months. We'll see....

A

ltc

Well, you better call PAG and tell them to remove all of the 5W-xx motor oils from their 'approved engine oil lists'.

Actually, 0W-40 allowed for a single 'one size fits all factory fill' for all cars being produced, no matter where they were being delivered.

ltc

Strange how Mobil has limited availability for the 5W-50:

http://www.mobiloil.com/USA-English/...ilability.aspx

ltc

FWIW, M1 5W-50 is factory fill in the Ford GT40, so you should be able to source it thru any Ford dealership.

kezcapt

ITC: I find it sad you feel the need to be flippant. My point was to echo Kevin's warning against using 15W50 oils not to dissuade those who want to use 5w50 oils. I think any conscientious owner should consult a competent mechanic in their area who has experience with the 996tt. This would be especially useful in the case of our brothers from 'Vegas where they operate in extreme environments. I also find your cynicism about PAG's OE recommendation pretty funny: they are not known for their tendency to compromise. In any event, if you have any laboratory science or mechanical engineering information to share then I would be very happy to learn from your input.

Oak

0-50 best of both worlds.

ltc

Not much moderation? I was just posting as a 996TT owner...I should have taken off my 'Moderation' hat, even though it didn't appear as though I was Modrerating a thread.

Flippant? Sorry, English is not my strong point and I'm not really a good Scrabble player.

If 0W was brought into existence simply due to Variocam, then why would Porsche even offer a 5W-xx oil on their list, especially when 0W is the factory fill.
Is there a disclaimer on the PAG approved oil list that says "5X-xx is to be used only if 0W-40 is unavailable and should be flushed and refilled with 0W-40 as soon as is practical"?
Why would Porsche simply not offer 5W-xx as factory fill?

Please go back and re-read your post. You make no mention of anything other than the reason for 0W-40 in VVT engines....or did I miss something?

P.S. I promise to leave off my 'Moderator' hat for the duration of this thread....so have fun.