The owner's manual lists several grades of oil that are permissible. Is there a particular grade that is favored more than others?
Note: I'm NOT asking which brand of oil to use.

Also, the owner's manual does not state whether to use regular or synthetic oil. Is synthetic OK to use?

I did a forum search and looked thru the Newbie thread but didn't find an answer to my questions. Since I was able to get my 87 S4 started, I can move on to items like an oil change.
Thanks. Not wanting to start an oil war, just need some high level information.

 

The chart in the manual also shows ambient temperatures, that's important.

Try these threads:
https://rennlist.com/forums/928-foru...sity-poll.html
https://rennlist.com/forums/928-foru...o-you-use.html
https://rennlist.com/forums/928-foru...viscosity.html
https://rennlist.com/forums/928-foru...-question.html
https://rennlist.com/forums/928-foru...the-928-a.html

 

I live in SC and use Driven DT50 15/50 full synthetic year round in my 79 that has an 83 supercharged motor. Has higher Zinc and Phosphorous than the Porsche A40 approved oils (over 1,000 ppm of both).

 

I like the Valvoline 20W50 VR 1 Racing Dino oil,it has higher zinc in it
When I get a noisy 928 engine putting this oil oil seems to make it run quieter
usually due to lower viscosity oils being used
it works great and its reasonably priced and pretty easy to find.

 

For all but the very coldest starting conditions, many of us get by with 15W-50 Mobil-1 synthetic. The 20W-50 that Stan uses is also good, assuming that you are following an aggressive change schedule as most of us do. Racing oils tend to have less corrosion inhibitors, since they are changed after every race session. I'm not sure that's ever been an issue with the 928 engines, so may not be important. If you drive the car as most road-going US 928's are driven, the features you look for in your oil will be 15w-50 to 20W-50 so the oil stays thick enough to maintain hot oil pressure. The ZDDP number is important for our flat-tappet cams and followers. Many "modern" fuel-saving oils have reduced zinc because it is tough on catalytic converters. "Modern" cam followers in those fuel-saving engines have rollers rather than a flat tappet face, so no issues for them with low zinc.

There will be more recommendations I'm sure. As a teenager, I professed to prefer brunettes, always admired redheads, and almost always ended up dating blondes. Which is best? The one that doesn't flatten your cam or collapse your lifters, allow excessive rod or thrust bearing wear, isn't noisy at start-up. A premium multi-grade will do that. The Mobil-1 I use generally has the red cap, FWIW. I hoard the 5-quart jugs.

 

Epic! I may need to ask you for permission to use this in my signature block

 

10/50, 15/50 or 20/50.

Pick the cold viscosity that is suitable for your climate.
When the oil gets hot, you want the 50 weight viscosity.

 

Definitely T-Shirt worthy material right there!!

 

Dave --

You are of course welcome to use it. Do you hoard 5-quart jugs with red caps too?

----

I apologize to those who might be offended by the post. It truly started out with the best intentions. But the words kept appearing on the screen, and I couldn't help myself any more. Know that I did leave out the part about finding my personal choice at WalMart cheap.

 

LoL. Thanks. I think though, for reasons of propriety, I will stick to what I've got.

mmm... the two currently in stock have sufficed for some considerable time.

 

No need to apologize. I've gotten great info and a little levity is enjoyable. In times like these, we need to have more fun.

 

Anyone who runs a 928 by definition is moderately to severely loopy- if such folks cannot handle a bit of "double entendre" they should sell the 928 to someone more worthy and perhaps visit the 911 boards instead!

 

Hello, How much zinc does valvoline vr 20w50 have?

 

IMO oils. Need to have at least 1,000 ppm of both Zinc & Phosphorous and that's in the UOA, so more than that in a virgin sample 1,100 - 1,200 ppm of each is a good target and why I use Driven DT50 in my 928s, 914, and wakeboard boat.

 

The whole zinc (really it's ZDDP that's important, not just zinc) fiasco started around 2001 when EPA regulations dropped the level of ZDDP (Zinc & Phosphorous) from 1200/1100ppm to 800/600ppm. Our engines (and most engines) have no use for ZDDP higher than the 1200/1100ppm levels.

Most oils in the popular viscosity range of 15/20w-50 have the necessary level of ZDDP. The only one I've been able to confirm 100% that does not, is Castrol non-synthetic 20w-50. I'm sure there is more than one, but I have yet to find any and I've spent an absurd amount of time looking.