Just wondering if any of you guys are running Motul 15w50 weight oil in your cars? I have stayed with Mobil 1 but a local shop is suggesting I switch over to this oil.

 

Motul Motorsport 300V series is one of the best oils, I feel it's superior to Mobil 1 but it's very expensive. If it was priced more reasonable I would be using it instead of Mobil 1.

 

I don't believe 15W-50 is a Porsche recommended oil weight.

 

I run it in my 993 - I plan to use in my 996 turbo the next time I change the oil (last service done at dealer as car was still under warranty). It is more expensive but it is a true synthetic not like what Mobil has become. It is more expensive but in the greater scheme of things it is worth it in my mind.

 

I think Dock is right 15W-50 is not Porsche recommended but I do know a few people running that viscosity, I went with 5W-50 which is Porsche recommended.

 

Are you using the Motul 300V series oil?

 

I don't know about 993 approved oils, just that 15W-50 is not approved for the 996 Turbo.

 

15/50 in summer Months, especially for track work, both 300v or Mobil Motorsport are pretty good... if running car over the winter switch down to a 5/40 or 5/50

 

most of the books and "experts" (which I don't consider myself as one...) suggest the Mobil1 0W40. I just go with that, although it's a very thin oil and here in Houston in summer month, I believe that a higher viscosity would be better. a friend of mine that has his M3 just delivered puts 5W50 in his engine....
Well, apparently nobody never blew an (stock) engine with 0W40, so why change it if it ain't broken, especially if repair costs of the engine are in the stratosphere... May be with EVOS you need to change to another oil type?

 

i keep stock of both 5w40 and 15w50 of MOTUL 300V. Not sure which is correct.

 

I am using Motul 300V 5w40 in my car. Considering that I will be replacing it every 5k miles, I don't see the cost as an issue. Sticking $300 worth of oil in a 100k car seems reasonable to me.

 

Gets pretty warm here most of the year, and winter temps rarely dip below 10-15C. My engine gets rev'd same way it would (though shorter intervals) on DD. So thinking play it safe go with the 50. New to P cars, can anyone advise whether there is downside to going with one level up on viscocity other than marginally slower engine response?

thanks

 

The 50 part isn't the big issue, it's the 15 part. There is a saying that 'no
oil is thin enough for startup'. That's an exaggeration, of course, but you
need quick flow to get oil to the valve train quickly at startup, and you mostly
want flow to get oil into the smallest, most important gaps, and to collect
and take away heat through bearings. Unless you're truly racing, and need
an oil to stay thicker at very hot engine temps (not ambient temps), you
may gain nothing with the 50 wt (does your engine temperature ever get
above 185-190?), and *will* lose startup lube efficiency with a 20x50. I
run 5w50 but I'd also be comfortable running 0w40. Thick is fluid friction,
not 'leather-soled protection'. F1 motor builders toyed with using *water*
instead of oil, and uniformly use very thin oils. Ultimately, do what Porsche
recommends.

 

When porsche suggests 0-40...probably they know the reasons...About the brand whether mobil or motul as long as it is full sunthetic it will be ok...i live in Greece with very hot weather and still use 0-40...it is good for valves and valve tappings to start up with 0 oil and not with 5,10 or15...
Also because discussion about oil can take many pages have in mind that oil pump at a constant time (lets say 60sec) and at constant rpm(lets say 4000rpm) can deliver more liters of 0 oil than 15 oil...as a result more oil circulates through engine resulting in better lubrication and better heat transfer...There is no need for a highly enginnered engine like ours to use 10 or 15 oil...

 

My understanding (please correct me if I am wrong) is that at -35C both 0W and 5W have the same pumping characteristics. The advantage of 0W is it reaches lower than -35C (to -40C).

Here are the cold crank specifics on each oil...

Low Temp Viscosity in cP

0W = Cranking Max - 3,250 @ -30C / Pumping Max - 60,000 @ -40C

5W = Cranking Max - 3,500 @ -25C / Pumping Max - 60,000 @ -35C

I believe in terms of cold start pumping performance the 0W shears to perform like 5W when the temperature is equal to or warmer than -35C (up to the upper limit of the cold start specification).

So unless you face temperatures colder than -35C, I don't think you will face any cold-start pumping issues with 5W.