IXLR8

I tend to believe the manufacturer's recommendations and according to Mobil, it is not.

This is much like any oil thread found anywhere. Lots of seat-of-the-pants observations and recommendations.

Bill Verburg

I guess the factory disagrees w/ you as well as most of the top trans guys

IXLR8

I guess they both disagree with the makers of the oil.

From the Mobil site...

Question:
Which Gear Oil Brand is Best for Porsches with Limited Slip Transaxles?
For Porsches with limited slip transaxles, I've heard that Mobil 1 Synthetic Gear Lube LS 75W-90 is too slippery for the synchros and that Mobil Delvac Synthetic Gear Oil 75W-90 is the preferred lube. What's your opinion?
-- Stan Simm, Winston-Salem, NC

Answer:
Mobil 1 Synthetic Gear Lube LS is specifically designed for limited slip differentials. It contains a nominal amount of friction modifier to satisfy the needs of many applications. Mobil Delvac Synthetic Gear Oil 75W-90 is not a limited slip gear oil.


Is Mobil Delvac recommended by Porsche AG? If so, where is that stated?

Bill Verburg

You are certainly free to believe whoever you want

I have a almost every Cup and RS and RSR factory manual for cars from ~'98 to '10, they all contain the same info

here's an example from th '07RSR manual


p17



SHC was renamed Delvac in the N. American market a few years ago

IXLR8

The question is, was it just renamed or also reformulated for other purposes?

Looks like Mobil is contradicting themselves. If I were a user, I'd ask Mobil to clarify. In my case, no worries as I use the Mobil 75W-90 LS

Bill Verburg

Some folks see conspiracies everywhere, as I have repeatedly pointed out, use and believe what ever pleases you.

The smart money will be placed elsewhere, though I'm sure that Delvac LS is fine too, it's just not necessary for cars w/ our lsd's , maybe there are some lsd's that will benefit, but not ours

IXLR8

Bill, where did you come across Mobil Delvac gear oil on the Mobil site? The only topic I came across is in the Q&A section when doing a search there.

Is there a product sheet anywhere on the Mobil site?

NC TRACKRAT

Alex-Here's the specs...
http://www.mobil.com/usa-english/lub...90_80w-140.asp
BTW, folks, I'm the one who sent in the question to MOBIL1....and I don't buy their answer.

IXLR8

I came across that same link that is not longer active.

You wonder who they get to answer the questions sent in.

NC TRACKRAT

Try it now...It works.

IXLR8

Thanks! I read through it twice quickly...I may have missed it but I did not come across anything specifying that it was OK to use in LS differentials.

fast_freddy

I had Swepco in my car and the gearbox whined like nobodies business. I replaced it with Mobil 1 and the problem went away in a few minutes.

NC TRACKRAT

...But it doesn't say you shouldn't.

Steve Weiner-Rennsport Systems

Mobil 1 LS has friction modifiers to ensure a smooth LSD without "stick-slip".

Mobil 1 Delvac is preferred for track cars where one wants more bite from the LSD and a little "stick-slip" in tight turns doesn't bother anyone. This also helps steel syncros.

Both products are fine, its all about personal preferences.

Gunter

O.K.
Found Mobil 1 Delvac 75W90 at a local OK TIRE store.
While refilling the G50, I also flushed the clutch slave cylinder.
Lots of dirty fluid in there. Where is the contamination coming from?

Long 6000 Km trip to UT/AZ visiting Escalante and Bryce Canyon again.
Used one quart total; very nice!

The 20 Mile uphill curvy route out of Torrey, UT, is a dream.

Since 15W50 Mobil 1 Synthetic is hard to find in Canada, I was lucky to get it at a Walmart in Yakima, WA.
2 containers with 5 Qts each for $50.00 total is a deal!