Porsche does approve 5-50 Mobil-1, so in warm areas it should be fine
for startup, but I would listen to Porsche's particular brand recommendations
too because viscosity categories are done by fitting in ranges. An oil gets
each of it's numbers because it is closer to the behavior of the standard for
that number than for either the higher or lower number. All 5 wt. oils don't
flow the same. Some are thicker than others. You'd expect a straight 5-wt
oil to be engineered as close to that standard as possible (at least that job
is simplest), but a 5w20 oil is much more likely to be a 'thin' 5 wt, than a 5w50
that has to stretch the large gap. So if someone decides that brand XYZ is
a better quality for whatever reason, and chooses their 15w50 (focusing on
the 'better protecting' 50 number), and this oil happens to be very close to
a 20w50, they are risking startup wear (running at any temperature below
full operating temp).

 

I generally agree on the "brand" issue; however, if the oil meets API, SH, or SJ classification (or ILSAC, GF-3, or ACEA in Europe) then the brand is probably less of an issue as long as it is fully synthetic (assuming it is one of the Porsche recommended weights).

 

I have an EVO9MR... its nearly impossible to find Motul in New Orleans without ordering over the net. If you search the web you can find alot of personal test on forums like my350z, etc... Motul is the best... hands down... the best testing I have seen is on diff noise... no additives or any other fluid was capable of silencing a clutch type diff... only Motul!!

I currently run Moble 1 - 0w-50 in the EVO9MR... you can defiantly hear the turbo is dry and has a distinct whine that goes away after idle for at least a full min. I always wait till this sound goes away before driving, just to be safe. I didn't have this issue with Royal Purple, however testing shows RP lower then Moble 1.

Personally test for yourself and get the oil you like best.
If you can get Motul locally... your a luck bastard.
AmsOil is next on my list and just as difficult to find locally!!

-Drew

 

thanks, this is pretty much what the shop was saying, that in the DC area, the temp doesn't get low enough for that to be an issue for the car. And on the flip side, they said that they've run it in many turbos including multiple race cars they work with and that they even see the engine running lower temp wise than with other oils.

 

Great oil, I swear by it . Truly a synthetic oil.

 

Hey Dock, do those standards address viscosity per se? In other words,
I am sure we can find a 20w50 that passes those, so unless they verify
and designate a more precise viscosity standard than the SAE rating,
those specs may be just about lubricity, longevity, etc, and wouldn't
protect us against getting a thicker or thinner oil within the spec. Indeed
some Porsche recommendations might *depend* on some oil's being at
the outer end of it's spec. Just a possibility.

 

Yes, in addition to the classification standards, viscosity is a player.

So Porsche wants the oil to meet the classification(s) above, in addition metting their temperature related viscosity resommendations. All of this is outlined in the owner's manual.

Up until last week I had always run Mobil 1 0W-40. At Kevin's (UMW) suggestion, I switched to Mobil 1 5W-50.

 

Coming from the motorcycle background, I find it interesting how each of various types of machines in my garage require different viscosities. I
would presume for each according to their function:

Ford F150 pickup - both 4.6L & 5.4L V8's call for 5W20 (the new low
tolerance motors required a thinner oil than the original 10W40)

KTM 450SX - (four stroke dirtbike - 1 cylinder - 450cc) calls for 20W50
regardless of what level of build you do to it!

Yamaha R1 race bike - (four stroke, 4 cyl - 1000cc) calls for 10W40
regardless of what level of build you do to it!

Porsche 996tt - 0W40

What I find so interesting is that both motorcycle engines (which run tolerances WAY smaller than ANYTHING from Porsche or Ford) call for a
10 to 20 W oil and they run MUCH HIGHER rpms than anything from
Porsche or Ford.

Yet, both Porsche AND Ford call for the thinner 0 to 5 W oils.

Reasons?

 

great site recommened by another member. Found some specs on the motul 300v 5w40 ingrediants here, probably not much different than the 50?
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1606542