What oil weight do you use in your Porsche??

[MarkRobinson]

I've used Mobil 1 15w50 for years, but most stores appear to be no longer carrying it...and when I find it it's $8.49/quart.

Even Walmart has stopped carrying the 4 quart jugs priced at $23.

On Mobil 1's site, you can plug in your car:

'91 911 turbo,
'88 944 Turbo S,
'86 928S,

For which it recommend a 10W-40 oil, eventhough Porsche was using/recommending 15w50 if memory serves. What gives??

Why no more 15W50, & why the oil weight change recommendation? I'm missed the train apparently...

[Targa Me]

I'm using 20w50 and that seems to be working fine.

[looneybin]

when did wally world stop carrying 15W50?
I just purchased (2) 4 quart jugs about 2 months ago

[Porsche-O-Phile]

I think Rick Lee posted about the lack of 15w50 M-1 a few weeks ago also. Fortunately I've got several gallons of the stuff sitting around, enough to supply me for the next few years probably. I also have a bunch of Royal Purple which is good also.

"Why'd they stop selling 5 quart jugs at $23 each?"
"I only ever see it at $8 a quart"

There's your answer, I suspect.

[UconnTim97]

Mobil 1 15W50. I also use it on some of my spoons.

[Rick Lee]

I'm down to one 5 qt. jug of Mobil 1 15W50. I bought four of them in the Wal-Mart in Henderson, NV a year ago. This last jug is for my bike. I just ordered three jugs Motul and, with shipping, it was still cheaper than paying retail for individual qt. bottles of Mobil 1 at AutoZone. Motul 6100 is the new oil for my 993 going forward. FU Mobil 1!

[MarkRobinson]

I thought it was wierd that all 4 of my cars take the same "recommended" 10w40 from Mobil 1, whereas before Porsche was using 15w50; why the switch of weights too??

[spuggy]

There's a lot of noise around oil, and especially the "designer" stuff...

Two highly-regarded Porsche independents I've been very happy with both have Shell Rotella T Heavy-Duty 15W40 as a shop fill for air-cooled turbos - I've run it for the last 30,000 miles or so in my daily driver and very happy with it.

Used it in my 944 for years before that as well.

Quite cheap (a factor when changing oil every 3000 miles - good idea on a 930, essential for track use).
Widely available, buy it anywhere (that's nice).
Good additive pack, boron/ZDDP etc counts (fine for flat-tappet motors)


No slippery junk added - so also fine for motorcycles with wet clutches, and increasingly used by those folks.

Best of all, it's for diesel motors - so designed for normal operating conditions that involve pressures/temperatures the average N/A gas motor should never see.

[Noah930]

Originally Posted by spuggy

Two highly-regarded Porsche independents I've been very happy with both have Shell Rotella T Heavy-Duty 15W40 as a shop fill for air-cooled turbos -

I used that for my 930, as well. But then the local auto parts stores stopped carrying the "old" formulation, and now have just the newer (non-ZDDP) stuff. So I've switched to 20w-50 (or I suppose I could just run the straight 50w stuff here in CA)--either Valvoline VR-1 or Brad Penn.

[VINMAN]

20w/50 in the summer 15w/40 Rotella or Chevron in the winter

[teenerted1]

Ultimate Motor Oil Thread or Why we hate CJ4/SM oils

[slodave]

Rotella T straight 40 wt.

[azasadny]

I used Amsoil 20w50 in my '74 911

[mikesride]

Not for street use version of Penzoil 25/50 has the highest conc. of zinc I can find up here. Works great over 300,000 miles no rebuild.

[Rick Lee]

I'd love to be able to use the Rotella stuff. But it's stupid hot here, so I need synthetic. And I just changed my engine and gear oil an hour ago. Such a pain in the ass on a 993. I don't want to do it more often than 5k miles. Gawd, it's hot in my garage now. Two hours after I jacked her up, my engine still burns me when I touch it.

[M.D. Holloway]

All the oils now are API CJ-4. The ad-pacs for pretty much all oil you buy retail will be the same. Sorry dudes - it is what it is. The base oils differ and thats about where it ends. There may be some that are hold-outs of API CI but its just old inventory.

[slodave]

Mine's not. I don't buy it at a retailer either. I go to Sawyer Petroleum. The Rotella I get is for diesel and seems to be holding out from change and supply is endless at this point.

Intended Use:
Mixed fleets combining large over-the-road diesel trucks with smaller diesel and gasoline-fueled light trucks and passenger cars; *Heavy equipment used for construction, mining, or quarry operations – in engines, transmissions, and hydraulics systems; *Detroit Diesel two-cycle engines (series 53,71 and 92); heavy-duty automatic, and powershift transmissions specifying Allison C-4 fluid or use of API CF-4, CF-2, CF or obsolete CE, CD and CC engine oils; Farm equipment with diesel or gasoline engines; *Mobile, marine, or stationary diesel engines (except those with silver bearings) in severe service or applications calling for API CF-4 engine oil.