M1 0w-40 going out of grade in 2500 miles;

[MikenOH]

A friend with a new Porsche Cayman has been changing his oil religiously after every 2 track events and taking samples for analysis. Everything in the analysis has looked good--minimal wear, low fuel %--except falling out of grade to the 100 deg. C viscosity rating of 11.0-11.3 in only 2500 miles between oil changes.

IIRC, 40W specs say that the minimum in this weight is 12.5;M1 0W-40 is rated about 13.5. Porsche specifies a minimum oil weight of 40W (0W/5W-40 oils).

Should this owner be concerned how this oil is protecting his engine if it falls to this level of viscosity when hot?
thanks for any help.

 

[default]

2 track events is a lot of wear and tear on the oil, might want to cut it back to changing every track event.

 

[Wampahoofus]

Perhaps he should consider a xW-50 oil or more shear stable xW-40, especially if he uses the car primarily for competition. I would be interested to see how something like Mobil 1's 10W-40 motorcycle oil would compare since it's lower in VII.

 

[dailydriver]

Maybe try the Motul 300V Trophy 0W-40??

(But this could get VERY expensive, VERY quickly, even at two events per OCI!

)

 

[m6pwr]

I wouldn't worry at all about the oil going to a heavy 30 wt vis, particularly if all the other uoa metrics are ok. Most xw40 oils are light 40 weights to begin with and can be expected to shear back in to the heavy 30 wt range in use. Castrol 10w60 TWS has been used sucessfully in the BMW M cars for more than a decade. It starts out a light 60 wt and drops like a rock to a heavy 40 wt in use.

 

[OVERKILL]

Is he running the SM or SN version of the oil?

 

[volk06]

Idk of this would meet the specs but T6 5w-40 would be an excellent oil for the job.

 

[Doug Hillary]

Hi,
MikenOH - There is insufficient supplied data to simply make a value judgement

To answer your question though, you have already supplied the answer: you say that everything in the analysis looked good ---- minimum wear etc. How was this judged against what criteria etc. etc.

The critical test has always been A3/B3 and its shear stability requirement - and in particular the HTHS viscosity

I've been involved with Porsche vehicles at the Nurburgring 24hr , I've also been satisfied that the Independent race teams using this lubricant trust it - as do Porsche!

 

[Ayrton]

I have gotten my oil changed, much less performance car too, with Mobil 1 0w-40. Twice did analysis only 200 miles into oil change for curiosity sake. Viscosity was already down to 12.34.

Mobil 1 0w-40 is in every Porsche engine when it leaves the factory. They surely know its characteristics.

The 11.0-11.3 you mention is still thicker than if he ran a common non-approved 5w30. It would probably be down to 9.5 after his short run.

 

[901Memphis]

You already said that the wear was good, why would you change anything unless there was an oil pressure problem? I don't see any reason to change anything he's doing except extending the changes but probably not a great idea for tracking .

I agree that we have insufficient data though.

 

[A_Harman]

I don't think he needs to go to a 50 weight, but maybe he should consider Pennzoil Ultra Euro 5w40. Yeah, I know no local auto parts store carries it, but Amazon is just a few mouse clicks away.

Or getting into boutique oils, Redline 10w40 or Joe Gibbs DT40 are very shear resistant. (Well, Redline not so much anymore; it's about equivalent to PUE 5w40.) Joe Gibbs DT40 is basically formulated for Porsches.

 

[OVERKILL]

Originally Posted By: A_Harman
I don't think he needs to go to a 50 weight, but maybe he should consider Pennzoil Ultra Euro 5w40. Yeah, I know no local auto parts store carries it, but Amazon is just a few mouse clicks away.

Or getting into boutique oils, Redline 10w40 or Joe Gibbs DT40 are very shear resistant. (Well, Redline not so much anymore; it's about equivalent to PUE 5w40.) Joe Gibbs DT40 is basically formulated for Porsches.


PU 5w-40 shears just as much as M1 0w-40.

 

[A_Harman]

Originally Posted By: OVERKILL
Originally Posted By: A_Harman
I don't think he needs to go to a 50 weight, but maybe he should consider Pennzoil Ultra Euro 5w40. Yeah, I know no local auto parts store carries it, but Amazon is just a few mouse clicks away.

Or getting into boutique oils, Redline 10w40 or Joe Gibbs DT40 are very shear resistant. (Well, Redline not so much anymore; it's about equivalent to PUE 5w40.) Joe Gibbs DT40 is basically formulated for Porsches.


PU 5w-40 shears just as much as M1 0w-40.


I doubt that. I have done calculations of the Temporary Shear Ratio for both oils, and get .927 for PUE 5w40, and .856 for M1 0w40. Do you have UOA's to back up your statement?

 

[Doug Hillary]

Hi,
A_Harman - You said this "Joe Gibbs DT40 is basically formulated for Porsches."

M1 0W-40 IS formulated for Porsche engines by Mobil via Porsche. Of course it's been this way for a decade or more

 

[MikenOH]

Thanks for all the responses.

The data that I've seen is the basic test, without the HTHS figure.

As wear number were below the universal averages and roughly what the first sample showed without the track days.

What prompts my questions was an article in the Dec. Panorama with Jake Ruby's 4.2L Cayman. Ruby went on to say in the article that one of the problems with the Porsche M96/M97 motors was high oil temps (not specified) but hat he theorized that many of the failures he's seen originally attributed to a lack of lubrication in high G turns might in fact have been the result of oil subjected to very high temps that had ceased to be able to provide proper lubrication. the 4.2L cayman in question had a GT3 front facia with larger air inlets that supposedly dropped the oil temps roughly 25 deg. F.

Anyway, that article but his recent oil samples and comments on low viscosity got us thinking about alternatives if the 0W-40 at these ratings look suspect. I guess the question would be if you were changing your M1 0w-40 oil with results like the one discussed, should you be concerned about whether the oil is providing proper lubrication.

I've been tracking Porsche Boxsters for the past 10 years using, M1 0w-40, 5W-50, lubromoly 5W-40 and Edge 5W-40. All are A40 spec Porsche oils. My mechanics--both Porsche and Indy--have tried to steer me away from M1 0-40 because they all thought it didn't offer the protection that other oils did. I have oil analysis reports from other cars that I'll try to dig up and post, but subjectively when I have switched from M1 0-40 to the others, the engine was much quieter, didn't smoke on start up and never exhibited the sticky/collapsed lifter noise on start up I had with 0-40.
Thanks again for your comments.

 

[SilverC6]

Originally Posted By: m6pwr
I wouldn't worry at all about the oil going to a heavy 30 wt vis, particularly if all the other uoa metrics are ok. Most xw40 oils are light 40 weights to begin with and can be expected to shear back in to the heavy 30 wt range in use. Castrol 10w60 TWS has been used sucessfully in the BMW M cars for more than a decade. It starts out a light 60 wt and drops like a rock to a heavy 40 wt in use.


Putting BMW's magic elixir in a Cayman probably wouldn't work.

It would likely go straight through the oil pan like alien acid blood through the Nostromo.

 

[Doug Hillary]

Hi,
MikenOH - Lubrication issues in high G turns is simply a factor of oil starvation causing cavitation and the likes. Such things happened in 928s and many other cars. An Accusump was used by some!

Porsche's test track - the Nurburgring - has many high G corners - I know from experience!

 

[CATERHAM]

As others have mentioned you haven't provided enough info' to conclude M1 0W-40 may become too light under track conditions.
If you provided the maximum oil temp's and minimum oil pressure values then have something to ponder.

I have a number buddies that track their Porsches without issue using even the lighter SM version of M1 0W-40.

And remember a few years ago Porsche ran the FUCHS Titan GT-1 0W-20 in the GT-3 based Porsche Cup series without any lubrication issues so the viscosity reserves running M1 0W-40 even after some shearing/fuel dilution are substantial.

 

[MikenOH]

Yes, I'm aware of that doug. What Raby was saying was that he thinks many of the engine failures he's seen -- originally attributed to oil starvation --are more likely engine failures due to oil thinning due to high oil oil temps.

 

[Doug Hillary]

Hi,
MikenOH - Well, to be meaningful his thoughts need to be backed up by analytical data which can be easily obtained with today's technologies

The data I've seen in the past leads solely to lubricant starvation. No lubricant of any viscosity will prevent damage in these situations - and the starvation only needs to be of very short duration