ronnie993tt

There's are entries on a 993 forum thread entitled "Mobil 1 Racing Oils, V Twin, etc., Zinc PPM" that claim V Twin has too much ZDDP implying long tern wear problems and cat clogging issues. M1 15W-50 with it's lower ZDDP level is espoused as the best option. Oil analysis posted here show V Twin to yield the most favourable readings. What do we think about this? Mike?

Kevin

You have more of a chance to plug your cats from leaking/smoking turbochargers than from VTwin. How many folks have replaced there cats in 10 years with VTwin. If that was the case, I'd rebuild the stock CAT's with high efficiency 100 cell units..

The other question is?? How many 993TT engines are running with M1 0W40??

Mike J

Yah, see my response in the 993 forum - and I have never seen a cat plugged due to excessive zinc in the oil in the car.

I do now know what Bill is getting at with the comment about long term wear problems ...

Cheers,

Mike

ronnie993tt

Thanks guys. Mine's had M1 15W 50 for it's first 8.4K miles and M1 V Twin since then and based on your thoughts I'm stickin' with it.

Basal Skull

It probably depends on how the zinc is actually working. Too much of a good thing is not necessarily good. I'm not sure if engineers have actually really worked out how zinc works. I know other slippery oil additives (that I have experience with in a prior life/career - and have lost turbo bearings with because I have access to it and used too much ...) work by being a mild corrosive, so that on the microscopic level, the peaks/craters you can see improved - the peaks bend. Too much and you can literally melt the bearing surface. It's like using really alkaline soap that melts you skin but you notice it is really slippery. I'm sure there's some concentration of zinc that is optimal. Bill seems to think v-twin is close to the upper limit.

ronnie993tt

So are we 993 tt guys 100% V Twin or 50/50 V Twin/M1 15W 50 mix to reduce the Zn level?

PiB993

I have been 100%* V-Twin for 3 or so years and just got this year done again with V-Twin. People are snapping their wheel bolts more often than replacing cats from what I can tell. To each their own. Who has been using V-Twin the longest?

*Briefly had 15w-50 but shop (now closed) did something to cause smoking (overfill, wrong filter, over tightened filter?) immediately drained and replaced with V-Twin.

chsu74

V Twin for 5 years

Quadcammer

same. no issues to report, but I don't do oil analysis either.

ronnie993tt

All of the V Twin oil analyses posted on this forum show excellent results. I'm wondering about this potential long term wear issue?

chsu74

Your long term experience would come from folks who rebuilds and races these engines. They were forced to find substitutes after additives changed. When that year(s) were is for them to say.

rlme36

I would find it interesting to hear an analysis on a tear down of a turbo engine and if the higher add package of Zddp was a contributing factor.

Mike J

One example is not enough. This is why I am skeptical about all the reasons often quoted - like observations of particular wear patterns in engines being torn down. If the same wear pattern was observed in a statistically significant set of engines (say 100+ or more), and those engines were closely documented on how, when, where they were used, all the servicing and what was put into the engine was the same on all the engine, you might have a chance to conclude which variable caused the problem. If not, its just an opinion. If may be right, but being an engineer, I am always asking "ok, where is the data to support that claim"?

The majority of 993 owners are not the original owners of their cars - and so even fundamental procedures like following a proper break-in sequence when new, or not driving hard when the car is cold may or may not have been followed, and those might cause issues later in an engines life. There are literally hundreds if not thousands of variables at play here.



Cheers,

Mike

ronnie993tt

As usual, you've hit the nail on the head Mike. Being a skeptic at heart, it seems to me there are way too many variables to isolate the long term impact of ZDDP levels. As far as I can see the only data we have are oil analyses which are very favourable to continued V Twin use.