NAM VET

I am not familiar with the straight lines on the above reports, but interesting that the viscosity has decreased so much, esp compared to your MINI, and also seems to have "used up" more of the ZN and Phosphorus.

I was thinking this afternoon on my 200 mile drive down to the Beach, went back to Charlotte for a single work shift, about oils and lubrication. I am no petroleum engineer, but have had an interest in engine lubrication since I first got a TR4 in '65. Engine oils have come a long, long way since then.

I know there is "shear" within an engine, and heat and dilution, and consumption of some of the properties of any auto motor oil, but I would think that all motors and oils do this, and but as long as a modern oil is not subjected to extreme temps, modern powerplants should likely have similar changes in their oils over time; I don't know why a GT3 motor would be more likely to show greater adverse changes in viscosity than any other motor, such as Thork's MINI above.

Anyway, if I were Thork, I would change to a different oil, and after two changes, (to diminish the residual Miller's oil in the system), and run another analysis. Me, I run Redline oils, and add just a little of their engine oil supplement with each change. I haven't done an analysis on our GT3 yet, though.

Makes one wonder why so many manufacturers recommend very long change intervals. Perhaps viscosity and anti-wear additives are more than sufficient for long engine life, and more is just not essential. The same considerations may apply to oil pressure, when is enough enough?

Hope all of you in the midwest are not threatened by the floods now.

all the best....

NV

Ur20v

NV, There are few important 'issues' that give the oil a hard time in our GT3's- high rev's, gear drives and high lift cams, these factors cause the oil to break down more than a cooking engine in 'normal' cars with their 'long life' oil and long service intervals- these are for fleet/lease cost reasons rather than engineering advances- diesel engines are even worse for this due to contaminates.

I agree, changing oil spec and or manufacture may provide more stability and longevity and further monitoring is required to establish some data on hopeful improvements in life.

Thork'sGT3

Great conversation.
I think for now I am going to monitor the situation by taking samples at 1000km intervals, starting this spring, ensuring that before sample is taken the car is fresh off of a good drive. Not idling for 10 minutes dumping "cold start-up" fuel mixture before draining. I have been using Millers in our vehicles for some time now and it is an excellent oil. Definitely going to make one change at a time to ensure the right steps forward are taken.
If there are multiple folks out there that have oil analysis results showing Millers does not work in their Mezger that would be good.
I don't think this is an oil problem, but rather an oil drain process issue, and the interval likely needs to be shortened. Other than the viscosity and fuel dilution, the rest of the results I am quite happy with.
Let's keep the discussion going. Learning lots.

Brent

Thork'sGT3

NAM VET - Sent you a PM the other day on something entirely off topic

LexVan

Does Millers have a 5W40? Use that in the summer months.

Macster

You can analyze the oil periodically but to me that is just too much work.

Based on the analysis I think you need to shorten the drain interval of your GT3.

7500km is around 4400 miles. Given the fuel dilution and 40C and 100C viscosity numbers I wouldn't run the oil past 7500km. I wouldn't run it to 7500km. You could run the oil to say 5000km and analyze it I guess and see what the numbers look like. But given how inexpensive oil is and how expensive (understatement) a GT3 engine is I'd just change it and put the money I'd spend on the analysis towards the cost of the oil change.

Oh, and given the results of the analysis I would not show up the track with anything but fresh oil.


I do not want to start an oil war but I have to wonder how Mobil 1 0w-40 would do under similar circumstances?

LexVan

Why would Mobil 0W40 improve his viscosities when we all know this oil exhibits classic shear breakdown?

Now, maybe Mobil 5W50 would help for his non winter months.

I wonder if this Millers oil he's running is a race oil or full synthetic street oil?

JB911

I've been using Mobil 5W-50, mainly because it's a good range for the hot weather her in S. FL . I don't think we'll ever see temperatures below 50 here ever again (laughs)

And I suppose you can trust Exon Mobil's products, they are the fathers of Petroleum(Standard Oil)
As far as I know they had the first synthetic oil and gasoline (from coal), and traded/gave it to the Germans before and during WWII in exchange for synthetic rubber technology.
They also developed the crucial high octane/anti knock fuel(tetraethyl-lead) needed for supercharged/turbo airplane engines during WWII(Standard Oil agreements with I.G. Farben as part of the deal)

I've never researched much about oils and fuels, but recall a F1 documentary on how secretive oil grades/brands are in the industry.

And in the case of racing oils, I'm sure the Cup car guys will disclose what they use :thumbs:

I have a 2 stroke/74 H2 and run castor bean vegetable oil, smells great

NAM VET

while it would be nice to have a "sticky" thread about our GT3 oils, I doubt those owners whose reports are worrisome would post there, in case they someday wanted to sell their cars. I won an oil and filter change a few weeks ago at a Porsche Club raffle, and when next due, will ask for Redline, but if they can't do that, just have them replace with my own supplied oil. Long decades ago, when factories put in "break in oils", and you could by little cans of GM break-in supplements, I used to change my oils within about 500 miles, and add a can or so of the GM stuff to my first re-fill. Have done the same on my lawn tractors, and other gas motors, even the chipper shredder! My son just got an expensive JD mower tractor, I told him to change his oil and filer ASAP too. For my prior flat tappet "built" Superformance Cobra's Ford engine, I ran Redline 0-40 with a bottle of the Redline additive, putting my ZN and Phor uo to about 3000 ppm, as no cat, just side pipes. Plus put on a NASCAR huge oil filter hung on a mount off of Ernie Elliot's engine, held something like two quarts to fill it!

There are more knowledgable people on this forum than me when it comes to motor oils. Back in the winter of '65, wiped the bearings on my TR4 trying to run 30wt in the cold Nebraska fall, and then had to drive that hammering engine with no oil pressure 1100 miles back to DC for Christmas. Ended the trip with 90 wt gear oil in the sump, but made it. Put new bearings in it, ran fine thereafter.

I was concerned enough about pre-oiling my Cobra's motor, put in a switched Canton oil tank, so always flipped the aircraft switch to push several quarts thru the motor before I cranked it. doing that on our GT3 motors would be bad for overfilling the sump, but it was reassuring to hear that gurgling of oil surging thru the lines, showing about 20# of pressure on the gage before i flipped the ignition switch up.

I really, really care about engine lubrication, just wish I knew more about it.

all the best, and GO CLEMSON!

NV

spiller

What do people think about a 10w60 in our engines? I do about 3000 kms per year and where I live the ambient temps vary from max 110 in the summer down to no lower than 40 in the winter. Is the 10w60 too heavy for the street? Would there be a better compromise for a car that sees the track only a handful of times per year?

LexVan

I would not.

mm450exc

I use Mobil 1 10W/60. Car gets a lot of track time. Cup cars use it as well.

NAM VET

The first owner of our GT3 did four track DE's when the car was new, and I have the service records from day one. He had it teched at a Porsche Race Shop in the DC area, and before each event, they put in 10-60 Swepco, then changed it immediately after the event. I presume their experience suggested it was best.

I had two oil temp gages in my Cobra, one out of the motor, another after the oil cooler, and into the motor. And a mechanical oll pressure gage. I swapped out the oiling system to high flow pump and larger AN lines, and a huge NASCAR oil filter, and found I ran higher oil pressure with 5-40 Redline than with their 50 wt oil. Also the oil ran cooler, too.

The viscosity and how it affects pressure and temps is complex, and each oiling system has its own variables. The cooler 40wt temps were likely because the thinner oil allowed a more efficient transfer of engine heat, and the bigger oil pump could push more of the thinner oil thru the motor with less viscosity drag thru the AN 12 lines, the pressure on my motor was measured at the return into the engine.

I don't know what oil viscosity would be best for our GT3 motors, but at some point, too thick an oil just can't get to where it is needed. For instance, 90 wt oil would certainly not be better at the bearings than a much less viscous oil. Our GT3 had four DE's early in its life, and has a gentle street life since. With 0-40 Mobil one, it would register just a hair under the top Bar of pressure at any speed, and show about 1.5 bar at hot idle. With the 5-40 Redline, it pegs the pressure at speed, and sits at 2 bar at hot idle. Like others on this forum, I long ago learned to never "load" or rev a motor until my engine and oil was good and warm.

Works for me.....

All the best...

NV

HarmonyJim

I have used either Mobil1 0-40w or more likely Castrol Syntec 10-40w changed every 3K miles. Blackstone analysis every other change. My fuel dilution on my 997.1 RS has always tested below 1%. Best money spent for peace of mind.

kiku

Interesting thread. I previously used liquimoly full synthetic 5-30w on my twin turbo Audi v8. This worked extremely well in track days and black stone analysis showed great flash point, dilution, zinc, etc.

Now, fast forward to my 7.1. No turbochargers meaning no need for such a high flash point.

Porsche dealer says use Mobil 1 only. I am curious if there is truth to this? Anyone using LiquiMoly?

Also, what oil weight is recommended during winter months here in Md/Va/dc area?

Thanks, trying to learn about this car....