Joe Weinstein

ebaker posted a good idea. The main mobil-1 oils for cars have had a
small compromise in their additives, removing an amount of beneficial
additives to help with emmissions. "Truck/SUV" oils do not have that
burden (contributing to mandated emmission standards) so they can
continue to focus on oil performance.
One trick to use is that viscosity in fluids is not linear. Do you remember
adding thinner to paint, or water to cement etc? A little added thinning
fluid makes a big difference to the whole batch, and it take a massive
amount of the thicker material to regain thickness. In our case, this means
that if you mix 4 qts of 5-40 SUV oil with 4 qts of 0-40 car oil, you'll get
half the extra additive concentration from the SUV oil, but the viscosity
of the oil will still be essentially 0-40 for the quick cold flow. In fact,
you could probably go with even more of the 5-40.
Tom, ask about fulltime race car oils. Many folks run straight single
viscosity oils. These rely on the native viscosity of the base oil, instead
of the modifiers that deliver the wide-range viscosity stabilizing of
the 'multi-rate' oils. A '10-50' oil is a 10-wt base stock with enough
viscosity moderators (which act with heat) to keep the oil film as
thick as a straight 50-wt would be at 100 deg. celsius.
For a race motor that is going to spend 99.9% of it's time at
one hot temperature, it is a simpler problem of choosing an oil
that will deliver the minimum needed oil film thickness at that
temperature, and it's safer to use an oil whose base stock has
every polymer long enough to deliver that thick a film, rather
than rely on additives.
Joe

1999Porsche911

Could it be? Are a greater number of car drivers finally realizing that the 0w40 oil SHOULD NOT be used, except for EXTREME cold temps? It's about time. I have been harping on this since it was introduced. For thoise who conitnue to use it, you are slowly detroying your engine. I suspect that Porsche, like another car manufacturer will eventually remove the 0W40 from it's approved list or at least emphasis that it should not be used in warmer climates. Otherwise, Porsche better start mass producing bearings and valve guides so they will be readily available as the miles on our cars start piling up.

tkerrmd

thanks Joe for all the info

tom

Dock

No.

Joe Weinstein

Thinner oil means more performance. Viscosity resists fluid motion by drag generating
heat. Heat degrades oil, and does so independently of viscosity so thick oil contributes
more to it's own breakdown under stress. The only thing viscosity aids is in film thickness,
which is necessary only to the degree of engineering tolerances in parts, due to
manufacturing limitations or differential thermal expansion. The very best engineered
motors such as formula-1 invariably use very thin oils. All oils get less viscous with heat
but as long as you have your cooling under control you have controlled viscosity.
Porsche has one of the longest continuing and current experience with high performance
and durability in motors. You may second-guess them at your whim and peril. In fact,
even if they ever hypothetically ever made a mistake about something like oil, there are
very few organizations, let alone grassroots rumor swells, that would have the credibilty
to say "I told you so" and have it mean anything. A stopped clock is right twice a day,
which is infinitely more often than some of our chatroom postings.

Dustman

I was very low and could only find 5w-40, not Mobile 1 of course. I doubt it matters that much or there would be much tighter control on M1 as a mandatory from dealer only. How often do you conduct an oil change? I've put 4k on.

AaronR968

M1 - 0w-40 is all we use in the new stuff.

"How often do you conduct an oil change?" --- every 3500 or 6 mo. to be on the safe side.

Red Comet

Yes, Pennzoil 5W-40 in the 996 Turbo, it is on Porsche's list of approved oils. It's generally hotter than hell here and the service department staff seem to know what they're doing, so I'm guessing there's some method to their yellow bottle madness.

The other Porsche dealer in the area told me they use M1 15W-50 in everything.

PorschePhD

5w40 will be fine. It is funny how people assume Porsche is having issues with these motors yet only a few have opened them up. One could speculate issues based on the 996 NA and that would be incorrect since tolerance are crap in the NA motor to begin with. Hence the line bore issue.

At the end of the day I have opened up and continue to build 996TT motors up and see no issues from this so called 0 or 5 w oil problem. Both this has been discussed among some of the top master Porsche techs and Porsche in the industry. Bottom line is for normal use, use what the factory recommends.

The oil has to be used as a hydraulic function as well as a lubricant and cooling device. The issues will pop up as I have seen using a thicker than necessary oil in the active valve train. This is not speculation but fact on what I have seen opening from building them. The single issue that the TT has is a thrust issues which is not related to oil. This is something that after some research and proper knowledge is very clear on case even from years past.

How many miles have I gone with this crap 0 or 5 weight. Over 50K. Only issue I have, my gas mileage sucks