G.I.G.

I'm not trying to start an oil debate, but I've commented on several posts stating that I would share some UOA results from the Millers CFS 10W-50 NT+ when I received them, so here they are. Since Millers is based in the UK, you don't hear about their oils much on Rennlist, so I thought I would share my experience here. I am on my 3rd oil change, and 2nd UOA with the Millers. I'm only sharing this for informational purposes, and to outline a few data points and observations. I have no affiliation with Millers Oils nor Performance Racing Oils (where I bought the Millers from). I also wanted to outline a few variations between the results from the samples that were sent to Speediagnostix and to Blackstone, both from the same used oil.

For context, I started doing UOA's on my 997.1 C2S at my first oil change in March of '19 with 50k miles on the odometer. I don't know what kind of oil was in the car when I bought it (I can only assume Mobil 1 0W-40) and I started using Motul Xcess 8100 5W-40 at that point. My car has burned about .4L (one bar on the digital gauge) every 550 to 600 miles consistently since I've owned it, and it has not increased with mileage nor decreased going to the Millers 10W-50. I'm currently at 61,500 miles on my car.

I started doing some research on the Millers after hearing that Barry "Baz" Hart of Hartec in the UK recommended it and uses it in the engines that they rebuild. I also read quite a few positive reviews on the Millers CFS oils and exchanged some PM's here with others that had positive experiences (and much more knowledge) with the Millers as well. My initial concerns were A) it's a "racing" oil, so how will it handle a 1-year/5k mile change interval and B) could there be any potential risk to the catalytic converters. Regarding possible catalytic converter or O2 sensor damage, I believe that argument has been put to bed. There are many here, myself now included, that are using non-Porsche approved oils with higher amounts of moly and other friction inhibitors without any ill effects on cats or O2 sensors. As far as the oil change interval for the Millers, I e-mailed them directly (because you can't believe everything you read on an Internet forum) and they reassured me that the detergent and anti-wear packages included in CFS line of oils were robust enough to last 5k miles. I was still a bit skeptical, so I kept the first fill of the Millers to 6-months/2,650 miles. The first UOA with the Millers looked really good with low wear metals showing and the additives holding up well, so I stretched it out to 1-year/3,700 miles on my second fill with the Millers. Below is my Speediagnostix UOA showing the most recent results with the 1-year/3,700 mile interval on the left, followed by the first Millers UOA (it says "Other" for some reason, that but that was the first Millers UOA I sent in), followed by my first UOA (mystery oil) and lastly the Motul.



One thing to mention if it stuck out to you is the oxidation value of the Millers. I'm glad I was given the heads up ahead of time so I wouldn't freak out, but ester based synthetic oils are going to be flagged with high oxidation values based on the testing parameters most labs use. The below quote is taken directly from page 3 of the Speediagnostix report.

"A high oxidation reading means the oil is past its useful life or it contains Ester base oils. If the oil is not Ester based, then reduce the drain interval. If the oil is Ester based, please submit a sample of the unused oil to establish the oxidation baseline for your oil."

Knowing that I needed an oxidation value baseline, I submitted a virgin sample of the Millers (below) the same time I submitted my first used oil sample. I also wanted to see what the additives looked like when new vs. used.




I remember reading here a while back that a member submitted a used oil sample to both Speediagnostix and Blackstone from the same oil and received two different results with fuel dilution. I can't for the life of me find that thread or that comment, but I figured I would try the same thing and send a sample off to Blackstone to compare (below). Sure enough, Speediagnostix states my fuel dilution from my most recent sample was 1.71 and Blackstone stated that it is <0.5. I don't take my car on short trips, and I drive off almost immediately after starting my car without letting it idle for extended periods of time. On the flip side of that, Blackstone called out moderately high silicon levels in my sample whereas Speediagnostix showed normal silicon levels. I don't use an aftermarket air intake, and I've changed my air filter twice since I bought my car, most recently last December when I was changing my starter. So between the two labs, there were some slight variations in the results, but nothing that I'm concerned about. For reference, I took both the Speediagnostix and Blackstone samples within seconds of each other mid-drain.



Lastly, I've been asked "why a 10W-50?" weight oil, as I know it is not a Porsche approved viscosity. After corresponding with Hartech, their recommendation for the thicker oil is because as the tolerances increase in the M96/M97 engines as the miles increase, they can benefit from a slightly thicker oil. It's my understanding that engine startup isn't our main concern, but rather warming up the engine properly and addressing hot spots in the engine, especially around bank 2, cylinders 5 and 6. I live in Colorado, but I only start and drive my car on mild winter days when the roads are clear. My attached garage is insulated (although not heated) and rarely drops below 50 degrees, at least not on the days I will drive my 911. A 10W oil is rated down to 0 degrees Fahrenheit, so I'm not starting or operating my 911 in temps remotely close to the lower temp limits of a 10W oil. More importantly, I've seen oil temps get up to 240+ on hot days when I'm running the car hard, which means those temps are likely even higher in certain areas of the engine. The Motul was looking like it was shearing out of grade based on a UOA, so I wanted to go with a thicker oil anyway. I added a 3rd radiator around the same time I switched to the Millers 10W-50 and haven't seen oil temps exceed 225 even on the hottest days, so I probably would have been alright with the 5W-40 Millers. The UOA's so far have been great with the 10W-50, so I'll continue to use it.

Overall I am very pleased with the results using the Millers and will stick with it for the foreseeable future. As far as oil labs go, it's probably more important to stay consistent with one so you have a baseline for your car. I'm less concerned about any one specific value than I am trends or seeing a spike in one value or another. Speediagnostix is a little more expensive, but they seem to do a more comprehensive analysis and that's what I started with and will continue to use going forward.

If anyone has any questions, just let me know.

hatchetf15

G.I.G - Excellent post. I also did some VOA comps with those two you mention and WIX. I did them for Porsche Classic 5w50 and M1 5w50 FSX2. The three sample results vary enough to be statistically significant. I was surprised methodology and test equipment could have such impact. I’m putting the Millers 10w50 for the same reasons you mention for my M96 3.8 build.

The UOA results I’ve seen from the UK 996 3.6 folks show more wear metals than you do for your 997 3.8. So that’s a real positive for you. It’ll be later next year before I have a UOA for the Millers, but I’m very curious to know if the 10w50 will help with my engine wear and oil shear. My numbers are ok with DT40 and LM Leichtlauf, but any less wear and temp shear is better.

G.I.G.

Thanks. Good to know I'm not the only one who has experienced differences in lab results. I suppose that is to be expected with different testing techniques and equipment, but I was a little surprised that a couple of the values differed as greatly as they did.

I share the same concern regarding oil sheer in these engines as you do, which is one of the reasons I mentioned for choosing the 10W-50 over the 5W-40 Millers. I'm not a tribologist, but the pour point with the Millers CFS 5W-40 NT+ is -48 centigrade, while the pour point of the 10W-50 is -42 centigrade. I'm not operating my car at the margins of what either oil viscosity can handle, so I think I'm good with the 10W-50. Besides, my ultra scientific method of swashing around a jug of the Millers 10W-50 in one hand on a cold day, with a jug of Mobil 1 5W-30 (the oil I use in my 4Runner) in the other hand produced the exact same results, so who can argue with that??

Just out of curiosity, who is doing your 3.8L rebuild or are you doing it yourself? Or is it completed already? Best of luck all the same!

silver_tt

Wow, that's a pretty large difference in fuel dilution values. Your 997.1 is port injected so it would seem the Blackstone results for fuel dilution are more likely vs the Speediagnostix value. Direct injected engines generally have a higher level of fuel dilution (up to 2% or even more in some cases). This seems even more probable considering that you say you don't do short trips.

hatchetf15

About 30,000 miles on the rebuild.

Fullyield

As between Blackstone v. Speediagnostix fuel dilution calculations, Speediagnostix will most likely be more accurate all other variables being equal. Why? Speediagnostix actually does a specific test for fuel dilution whereas Blackstone’s fuel dilution is an estimate but is not from a specific fuel dilution test. That is part of the reason the Speediagnostix test is more expensive. Correctly pulling the sample can also effect the fuel dilution test.

Hella-Buggin'

I have a SpeedDiagnostix of Miller CFS as well. I blended 10/50 & 5/40 though. So I guess a 7/45?

G.I.G.

I wanted to post a follow-up with my latest UOA from Speediagnostix. I used the same oil (Millers CFS 10W-50 NT+) as I have over the last several oil changes and things continue to look pretty good. I thought I would have put more miles on my car this past year vs. the year before, but I ended up putting a few less miles on my car than anticipated. So this sample is on par with the previous sample at 1-year, ~3,500 miles. The additive package continues to hold up well compared to the virgin sample of the Millers I sent in a while back, and the oxidation value is pretty consistent as well for an ester based oil.



As you can see from the results above, high levels of tin and vanadium came out of nowhere. I sent Lake Speed Jr. an email inquiring if they could retest for those two values, and below was his response.

"Thanks for the note. I suspect the remains have been discarded, but I’ll check.

Either way, I would not worry about it. The pattern we’ve noticed is the products with high levels of esters and additives can sometimes show these anomalous spikes of Tin and Vanadium. I have a theory that it could be from the foil seal, but we have no proof of that.

At any rate, don’t worry about it right now. Let's see if it was just an anomaly like the others we’ve seen."

Based on Lake's response, I'm not worried about the results. It seems as though ester based oils can trigger some odd results, like the oxidation value, that just seem to be anomalous compared to standard synthetic oils.

Overall, things continue to look consistent and overall pretty good. I am still receiving low but consistent fuel dilution. Again, I don't take my car for short drives and I ran the snot out of my car right before doing my oil change, getting the oil temps up to about 225, so I'm not sure if there is anything I can do differently compared to what I have been doing. Other than that, it was just another year of happy motoring. I'll update this thread again next year for anyone who is insterested.

silver_tt

These oil analyses are from a port injected 997.1, correct? Readings like 1.53 and 1.71 are WAY too high for a port injected engine and would only be acceptable on a direct injection engine. Lake should not be putting a green check mark next to your fuel dilution, I would check back with him about that ASAP as it looks like you have an issue.

Readings for fuel dilution form Blackstone should be ignored as they are approximations based off of the flashpoint and nowhere near accurate. Speediagnostix uses GC and FTIR both, which is much more accurate.

Thank you for sharing the information about esters.

G.I.G.

That is correct. My car is an 997.1 C2S with a port-injected M97 engine. Unfortunately most people post Blackstone UOA's, so I haven't seen many from Speediagnostix to compare the fuel dilution to. One thing to note, however, is that the fuel dilution and my oil consumption has been consistent during my ownership. I've owned my car three and half years and have put about 15k miles on it. I don't let it idle to warm it up, and I drive it gently until it comes up to temp. I burn about .4L of oil every 600-800 miles, and it's been that way since I bought the car in March of '19.

I'll send Lake another note to see if he has any thoughts on the fuel dilution and report back.

silver_tt

Normal fuel dilution for port injected engines is < .5% (it's < 2% for DFI engines). That should definitely be addressed and Lake needs to provide an explanation why he is passing that value with a green check box. I literally was having a conversation with him by email two days ago about this so it is disappointing that this is getting missed. The intake form asks the year and model of the vehicle the sample was taken from but this was apparently missed in your oil analysis and previous ones as well.

We have been discussing this here:
https://rennlist.com/forums/997-foru...l#post18435930

G.I.G.

That is interesting, as I just received this response from Lake. I specifically pointed out that I had a 997.1 with a port injected engine.

"Thanks for the questions. The fuel dilution of 1.5% is typical for these engines, so you are good. We flag fuel dilution if it goes over 2%.

In regards to the oil consumption, have you considered trying the Driven DI40? Some engines just tend to use some oil, so I would not be worried about it unless it increases."

I'm not sure, but maybe he confused the M97 engine with the 9A1 DFI engine, since he mentions DI40 oil (which is specially formulated for DFI engines)? I'll chime in on the other thread as well.

silver_tt

Wow. Lake doesn't know that the 997.1 is port injected apparently. You are correct, DI40 is specifically for direct injection engines like the 9A1 -- DT40 is most appropriate for port injected engines like your M97.

G.I.G.

In the spirit of consistency, I wanted to post my latest UOA with the Millers CFS 10W-50 NT+ from my annual oil change. I put slightly fewer miles on my car this year compared to last, but everything appears to look good and consistent from pervious years using the Millers. Wear metals (Aluminum, Copper, Iron, etc.) continue to stay in the low single digits, and the additive package in the Millers is holding up great with my 1-year/3k-4k mile OCI.




As you can see, the tin and vanadium were high and flagged appropriately. This first came up last year, and my initial thought was that it could be a one-time anomaly. After exchanging some emails with Lake at Speediagnostix after seeing similar high levels of tin and vanadium again this year, I decided to send in a new virgin sample of the Millers (below). We both suspected that Millers may have changed their formulation, which would cause the deviation from the first virgin sample of the Millers I sent to Speediagnostix several years back. That appeared to be the case, as you can see in the latest virgin UOA on the Millers.



Lastly, my oil consumption has remained consistent. My car continues to run great with no other issues.

Run_Amok

Great information. Thank you for posting.

If I understand correctly, you attribute the lower oil temps to the addition of the third radiator–is that right?