Paul902

This overlooks the issue of how much Zn and P are in one's diet, and thus the quality of the additive package!

JasonAndreas

The 964 and 993 were originally delivered by the factory with a 5w oil (5w30 until MY92 and then MY93 began 5w40 Mobil-1 I believe, 0w40 started in MY98(?) and every 964/993 serviced at the factory since then has been filled with it?).

Charles Navarro

My '91 has a factory fill sticker for a 15w40 Shell product (non-synthetic) which coincides with what the owners manual and my Bently "Technical Data Without Guesswork" states also as the correct viscosity. The chart matches up identicly to the one I posted on another thread, where 5w30 oils ~-25F to 32F operating temperatures.

JasonAndreas

What north american dealers did prior to delivery is another story but your 964 left the factory with shell synthetic oil.

The temperature range (that Porsche use in their oil TSBs -- I've just recently moved and can't post TSB content just yet) for 5w30 mineral oil is -25C to 20C and for a synthetic 5w30 the range is -30C to 40C.

Tuner1

Very interesting. Why is everyone suggesting 15W50 or 20W50 if a 40wt was the factory fill? With the improvement in motor oils over the last 15+ years there should be no reason to need anything beyond a strong 40wt oil and the lower viscosity at operating temp could free up a few HP and keep the oil temps lower vs a 50wt.

Tuner1

Hey Brant, could you please tell us some of the other oils that you did UOAs on vs the Redline 10W40? I plan to use the Redline in my 964 so I am curious

BC

http://www.bobistheoilguy.com/forums...6906/site_id/1

Fabio421

Any thoughts on adding Molly to replace whatever protective properties are missing in these new oils?

Charles Navarro

There are many species of moly FM (friction modifier) additives and they all don't work as well for both wear and fuel economy increases similarly. Just adding moly isn't going to cover up the problem of not enough AW additives. May help your fuel economy though.

Most of the modern CJ-4 and SM rated oils do have moly already in them.

For example, Swepco 306 15w40 has good Zn and P, alot of the boron AW additive, and a healthy dose of moly too. They're covering all bases and have a very well formulated product.

On the other hand, Brad Penn doesn't have any moly whatsoever.

RallyJon

I remember reading that. Looks like the guy put 20W50 in his Audi and called it 5W40. Best performing 5W40 at high temps evAr!

BC

Well ****, I never saw that. Where does it say it was 20/50 or is that an assumption on your part because of its results in the engine?

Stealth 993

Can we have a sticky with cliff notes?

RallyJon

Cliff's Notes? I'll give it a try...

It started off months ago with some anecdotal data that modern fuel efficient and emissions friendly oil formulations were missing some key ingredients that are important to our engines. Easy solution: use a high grade non-SM oil that has at least 1100 ppm of P and Zn and don't worry about it. Or use a bit of additives to pump up the 20 gal of SM oil you just bought until it's gone. All very sensible stuff.

Then things began to get weird.

Diesel synthetic oils begat motorcycle synthetic oils begat the first discussion of non-synthetic oil ever seen for a post '89 911. Simultaneously, oil weights were up, too. The old 0W40 became 5W40 became 15W40 became 20W50. For track use and sustained Autobahn speeds, right? No, for going to the supermarket for groceries, too.

And it turns out that the heavy sludge makes more power, even! (Who woulda thunk?) Not just that, but even in cold climates, we need to use heavy weight oil now, because--get this--the gaps between the cold bearings are now too vast for normal oil weights. Why, some oil is so thin it can drain right out between the aluminum atoms in your case, then you'll have no oil at all.

This whole topic has jumped the shark, and what started as some very constructive ideas for fixing a very real problem has evolved into a crazy bandwagon of 993 owners scratching their heads at where they'll find pure unrefined organic extra-virgin straight 60-weight (a preview of next week's recommendations) which is the only proper oil to keep your engine alive.

AOW162435

While informative, this thread has gone over the deep end. I'm sticking with my sub-par Mobil1 15W/50.

I'll consider bludgeoning myself with a blunt object should my engine grenade as a result of my reckless lubrication protocol.



Andreas

Amfab

Andreas, that's fine, as long as you use a good filter to remove the dust from the oil. . .