Benny771

Any reason to sway towards one or the other? I have a 1989 930.
I have read that Swepco is a good choice but Royal Purple i can get close to home (canada Ontario). Its a weekend car that does not spend any time on the track............................

Thx for the advice in advance.

pdqcarrera

Can't go wrong with Swepco. Been using it for decades on street 930 & race Porches. No matter temp, altitude, work rate ... always prove eliable. Couple of times shop talked me into trying something different the years never worked as well. Always change back & happier. Never ever again! ;-)

Benny771

Thanks for the info.... Im glad someone answered..

mel_t_vin

Benny, what gear oil did you end up putting in your G50.50?

Bruce Eyring

305000 miles on my '88 930.... changed to 201 at 60,000 miles....absolutely quiet...never a problem....never touched the transmission....Swepco 201 is the standard...period!

mel_t_vin

Congratulations on eclipsing 300000 miles in your 930! A significant achievement, indeed.

I'll agree with your statement, regarding a 915 box or a 930 box...but not a G50. For his application, the OP should've gone with the synthetic Royal Purple vice the conventional Swepco...or, considered Mobil Delvac, Redline, or Amsoil.

LexVan

I thought Mobil Delvac 75W90 was the gold standard for this car.

mel_t_vin

Many, myself included, believe it is, for the G50 boxes...and the Getrag variants in the 944/964/968. Not sure about the 928 box but I suspect it's a Getrag-derived variant, as well. Though, some folks prefer Redline, Royal Purple, or Amsoil to Mobil.

Regardless, I think the primary take away is that the Getrag-derived boxes with the Borg Warner syncros are "happier" with a synthetic, vice a conventional, gear oil like Swepco.

Swepco, on the other hand, is the gold standard for 915 and 930 boxes.