Charles Navarro

Nope, not related, but I know where there is a set of Barney's head with "Navarro" on it and I'd love to have one for my office wall.

And I'm glad I can be of help!

Baggerdude

I just spent a half hour reading this thread. Confusing at times and not all that scientific. Lots of opinions based on some experience or other.

I have quite a bit of M 1 15/50 gold cap in stock. I've used the red cap for years in my cars and motorcycles with good results.

I plan to continue to use M1 15/50 in my 993. If it causes some problems, well ... so be it. But, I would guess that there are many situations that occur to cause some sort of part failure in vehicles that is not dependent on just the oil one uses.

Speaking of opinions .... here's mine. Use what ever lubricant you wish. Dino/synthetic or whatever. But, I'd use what Porsche recommends. Change it according to Porsche's recommendation, too.

breale01

Baggerdude, I know you're waving the white flag (so am I) but, note that Porsche doesn't recommend 15W50.

Bill Verburg

In the owners manual for a 1995 993, it states
Engine Oil Recommendation
ambient temps mostly greater than 50F 10w/40, 15w/40, 15w/50 synthetics

or 15w/40, 20w/50, 40 mineral based oil

API SH

Charles Navarro

Even up to 2004, the owner's manuals for the Turbo, GT2, and GT3 called for an SH or SJ rated oil :-)

Slow Guy

But not in the current "Porsche Approved Oils" listing, and I suspect oils have changed greatly in 13 years. This is only a comment on whether you're saying you're sticking with Porsche approved oils only, not a reference to whether 15w50 is good for our cars.

FWIW, my car is on my lift right now for an oil change (among many other things) and Swepco 15w50 will be going in this time.

Bill Verburg

The current list is directed at and appropriate for current models and backdated for consistency and compliance w/ current emissions standards, I have no problem ignoring the factory's recommendations for 997 as being the LAW for 993.

The current oil standards were promulgated w/ an eye to emissions, ZDDP being regarded as bad for cats, was reduced as a result.

The emissions folks are now going after tire manufacturers, banning the use of certain chemicals used in compounding or production

while there may be oils w/ more ZDDP I will probably use M1 Extended Performance when my supply of old M1 is gone, call me old fashinoned but 15w/50 and 20w/50 have served very well and EP seems to have a reasonable % of ZDDP

Black993

So what should I put in when I do my oil change this time. i run Mobile1 in everything the Subaru and the G/F's car, and have no problem with it in the 993. Just not sure on which weight is best? I assume climate makes a difference in selection?

Headed now into the fall in Florida, what would you all suggest?

Slow Guy

Black, I won't profess to be an expert at this by any stretch of the imagination but the one bit of advice I would give is to stay away from the 0w(xx) weight oils, stay with a 5w40 or higher, and if you're going to FL I would definitely consider higher. This has been discussed in this thread a couple of times, I'll see if I can find what pages it's on later tonight.

Other than that I will make no other suggestion, one's enough.

cgfen

Why?
O weight oil is "thinner" than 5 weight oil at ambient temperature which may result in better initial oiling and resultant less engine wear at startup.


that said, my last fill was 5 - 40 weight also.

cheers

Craig

Bill Verburg

0w/** works fine w/ a newish tight 993/964 engine but will blow right through an older looser engine. Again current factory recomendations reflect their experience w/ newer equipment or their desire to profit from rebuilding the old stuff

face-ache

my 98 has used M1 15-50 since day one, @ 65k miles, it will do 3,000 miles before it burns a quart and has no issues ..

Slow Guy

It isn't a "thinner/thicker" (viscosity) issue, but Charles Navaro is far more qualified to explain it than I am so hopefully he will chime in here.

When I previously ran 0w40 in my 993 it went a little over 2k miles (between oil change) without needing to add any oil. I'm at 72K mi. right now. It has not been rebuilt in any way (unless you count my SAI Check Valve replace and system flush ).

Steve Weiner-Rennsport Systems

Craig,

There are some issues now surfacing about the use of 0w-40 oils in these cars and seem to be largely contained to North America.

NA spec cars have a clutch pedal interlock that prevents the engine from being started unless the pedal is depressed. This puts a huge load on the crankshaft's thrust bearings and we've seen premature wear when using the light oils that don't provide sufficient lubrication for those heavily loaded components.

JMHO, but I would not use anything lighter than 10w-40 in these cars.

Doug Hillary

Hi,
Steve - You said this:

"There are some issues now surfacing about the use of 0w-40 oils in these cars and seem to be largely contained to North America.

NA spec cars have a clutch pedal interlock that prevents the engine from being started unless the pedal is depressed. This puts a huge load on the crankshaft's thrust bearings and we've seen premature wear when using the light oils that don't provide sufficient lubrication for those heavily loaded components."

Can you please proved quantifiable evidence to support this statement?

SAE40 lubricants (such as 0W-40) cannot be judged to be "light oils", they are accepted in Tribogy circles as a "heavy" grade in the normal range of engine lubricants that spread from SAE10 to SAE50

Factory fill for Porsche engines from the 356 onwards was indeed a SAE30 or SAE40 grade lubricant well into the late 1970s and it (SAE40) still is today (with the exception of the V6 (VW) Cayenne)!