Edward

Well, I was going to go with the Shell Rotella synth in 5w/40 because the M1 5w/40 (diesel-truck-turbo) was "only" an SL-rated oil. Well, seems like the new batch my Walmart got (in 4-qt jugs) now has the SM rating (mine must have had old stock??). So I decided to go with the Mobil 5/40 ...from what I've read (and heard here ) the additives package of the "diesel/truck" formula can only be beneficial to a street-driven car. Just thought I'd pass this along...


Edward

cgfen

it's been working well for me AFAIK.

cheers

Craig

jcb-memphis

5w-40 is working for me....fwiw.

Paul902

Isn't SL "better" than SM?

Edward

Hey Paul,
SL is older; SM is its successor. As to "better," from what I recall the "conventional" wisdom is to get the latest spec. But the "better oil" I think has more to do with which oil has the better properties and additives package. From what I've read, the M1 5w/40 truck-diesel oil has got a good amount of zinc etc. (zddp of 1200) ...which is one reason I was considering both it and the Rotella synth.

Thanks, Craig, jcb ...good to know

Edward

RallyJon

Been half a year since the last huge ZDDP thread petered out. Given the hysteria, there must have been at least a dozen or so 993s running on SM oil that have had catastrophic engine failures since then.

C'mon guys, post 'em up. :crickets:

Tango635

Well, there's crickets only because this applies only to high performance engines............just kidding, sort of. There are some fairly credible folks who claim this to be true, Steve Wenere for one. But about the Rottela 5w40, i read second hand that it too has a 1200 ppm ZDDP content.

Edward

Sorry guys ...am feeling a bit dense here and am missing the sarcasm. What exactly is your point ...that I am clearly missing?

Edward

Steve Weiner-Rennsport Systems

LOL,..Although I think I'm all finished with posting into oil threads, I'd simply mention that shops who rebuild engines and repair these cars generally don't post with all their experiences and oil-related issues in public forums so that database is unavailable.

I do see such things in professional Porsche Technician Listserves that are not open forums.

My advice has been to use a good product and don't leave it in the engine for 6-8K. Our experience is that oils containing (at least) 1200 ppm of ZDDP provide sufficient protection of all the critical engine components so that would be something to consider.

Edward

Thanks, Steve. As always, your are the man!! ...not to mention it's always great to see you here!

Edward

Steve Weiner-Rennsport Systems

I'm here a few times a day but usually in the "quiet" mode,...

RallyJon

Just that the tone can sometimes push a bit too far toward the hysterical. As Steve points out, there is precious little in the way of data that's available to examine.

It's not so much that I expect the engine builders cabal to report all they see publicly, but there seems to be a dearth of owner experiences--which one would expect to be posted--now that most oil (including the oil used by most dealers and specialists) is so inadequate.

Steve Weiner-Rennsport Systems

JMHO, but I wouldn't put too much stock into "owner experiences" when it comes to oil. One should speak to people in the industry to get a snapshot of their collective experiences.

Just remember, "Everything is always OK up until the moment that it isn't", and that illustrates most personal experiences.

Edward

What Steve says. Which is why I try as best I can (whether it's about oil, repairs, mods, whatever...) to get opinions from those who see these things far more frequently than a given owner limited to his car's experience. The latter offers some valid insight, but the former offers breadth and experience.

As to oil (or shall I say "back to oil"), from all I've read the Mobil stuff ain't crap, has "decent numbers," and given my 10-11K annual mileage, 2 oil changes/year, and no longer tracked, I think I am making a reasonably informed decision to go with the M1 5w/40 TDT as my new brew. If anyone has any compelling evidence to share to the contrary, I am all ears.

Edward

Tango635

For the record I deeply respect the opinions and experiences of folks like Steve so I, for one, hope he keeps posting on oil threads. After all he has seen hundreds if not thousands of engines torn apart.

I have not come across any information good or bad on the M1 5w40 you are considering, but I have read that the M1 20w50 V twin motorcycle oil is supposed to be good stuff, i.e. high ZDDP levels.