bgoetz

So I had my second oil analysis, this time with Motul 8100, the first was Mobil 1 5w-30. Consumption was similar with both oils, I had listed 3 qt for the Mobil, but forgot the previous owner added a little. The one thing I noticed was that the Motul looked strange, really gray looking. The first analysis showed a bit of lead and iron and they indicated that the lead was likely a particle streak. This time around both were still present, but had came down, which I suppose is good.

What level of concern should I have regarding these two wear metals, their comments don't seem too concerning. At what point should I consider investigating further?

Any thoughts on the Motul vs the Mobil, their additives seem drastically different. I am still searching for the perfect oil and am considering giving Driven a try next, but how about the Mobil vs Motul?

fernando.

I'm going by personal experience so take my post with a grain of salt.

Motul doesn't get burned as much I find, and when I do my oil change 5,000km's later (3,100 miles) the oil is still golden, unlike other stuff I've used Mobil, Castrol, even the synthetic $10/qt Acura oil from my dealership goes black/really dark brown when I change it and I find my car drinks the stuff.

I bought the car in 2011 and used Motul up until the past 3 oil changes when I tried other stuff I had available to me at work, but I'm going to switch back to Motul next oil change.

But then again, this is just my eyes and what I see, I've never sent oil out to be analyzed so maybe I should start doing that.

bgoetz

Consumption wise these were the same, but to me the color seemed odd, not really black, but gray. Based on the sample results there was really nothing to explain my observation, and really for me it was just simply an observation not a concern. I am a bit more concerned with how concerned I should be about the iron and lead.

boyguan

I really like my 8100 oil. I've done 10 track days and black stone said I can do more

zeroptzero

Is Motul 8100 a cheaper line of the Motul brand ? Motul Oils that I've seen in the past always had tons of moly (anti-wear additive), your oil sample had almost no Moly ?. It looks like a very average oil to me in terms of composition.

You had a large amount of make up oil during the interval. You wear numbers look okay for a short run, I would have expected better numbers given the amount of make-up oil added during the interval. It is weird how some S2000's show different amounts of copper and lead, my engine's UOA had more copper but no lead. Your iron wear is okay, it would be good to see less lead IMO. Your sample showed almost no fuel, no coolant, and viscosity which was good. There wasn't anything terribly wrong with the results, it would be good if the lead numbers came down in the future but every engine wears differently.

I would try a different oil next time. I'm not familiar with the Motul line but they had some oils that had better additive packages last time I seen UOA's of that brand. I'd suggest Castrol Edge Titanium or their new extended performance oil, or a different Motul oil if there is one with a better additive package (higher moly), or Amsoil signature series, or Redline if cost isn't a factor.

I posted up a sample of Redline 5w30 recently if you want to check out that post , we drove about the same miles, but I had one quart of make-up oil. https://www.s2ki.com/s2000/topic/110...-oil-analysis/

bgoetz

Thanks for the thoughts J!

I thought about the makeup oil and how it might effect the results a bit after my first test. Here are my thoughts, for things like wear metals, I am not sure how big of a difference that it will make. Unless oil is going past the rings or there is a big dump through the PCV, I think the majority of oil lost in these engines is from foaming and vaporizing of the oil, at which point it is lost in the combustion process or through the PCV (which theoretically would still be through combustion). But just based on the fact that I lose oil, I have not once had a hint of burning smell and/or smoke and loss seems to track very closely to time spent at high rpms, I think most is lost in vapor, this is just my theory. If this is the case wear metals should not really change as metals don't really volatilize. So figure you lose a quart, the concentration of metals would now be higher, until you add a quart back. If this is the case it WOULD skew additives though, because say they are not lost as oil volume is reduced, their concentration to increases. The problem is you add more with fresh oil, so their concentration stays high. I think milage before actually draining and refilling is a bigger factor on wear metals than makeup oil. Makeup oil is a bigger factor on additive metals than milage, just my thoughts.

With regards to the Motul, 8100 is just under their full race oil and recommended for cars that will see a combo of street/track use. At $13 a quart it isn't cheap. I do agree that other than more zinc the results were not impressive at all. I will give some driven a try as it has some anti foaming agents that are designed to reduce the volitilization that I was theorizing above.

Just to clarify your thoughts on the iron and lead, you read that as more of a healthy engine that is just wearing differently as opposed to a bearing maybe starting to go?

zeroptzero

The amount of oil being added isn't a big deal. I think adding a lot of fresh oil does skew the results a bit, exactly how is anyone's guess, sometimes the labs account for that but they didn't say much about it. No biggie.

Iron wear in that sample is perfectly fine, I don't see any issue with that. Lead is the one item I hate to see on the increase, that is purely bearing wear. Your lead numbers aren't terribly high to indicate a failing part, but it did increase. Just before I lost my factory motor my lead wear spiked to 15 ppms, where it would normally run around 1-2 ppm. The actual number for your bearing wear isn't terribly high, but definitely keep monitoring it with UOA's to make sure it isn't on the rise. If you see lead rising it could be a sign of a bearing going bad, if the lead reading stabilizes or drops on the next UOA then it was just an intermittent spike in wear due to driving conditions or oil properties.

I have no idea why the oil would exhibit a greyish colour, generally speaking oil colour means nothing in terms of light, dark, etc. Now certain wear metals will change the oil's appearance, mostly by light reflecting sparkles or metallic particles suspended in the oil. It would take a huge amount of lead to change the oil's physical colour appearance so I would not suspect that with just a 4ppm reading.

I don't have any issues with Motul oils, I just think if I was going to use Motul I would use the formula which has the higher concentration of moly additive, and ester base oil. You don't seem to be getting that in the 8100 series oil. Motul and Redline have very similar approaches to their oil products, high moly anti-wear additive with group 5 ester base oils.

bgoetz

Actually my lead decreased, last time it was 9 this time 4, so I guess I should feel even better about that!!

Fokker

I'm sold on Amsoil Signature Series personally. I'm fairly certain I haven't had to add oil since the switch over (can't remember doing so) and it stays fairly golden even after 5,000+ miles of use. I'm going to send the current change out to be tested when it comes time replace again.

zeroptzero

That is correct, I didn't notice it before.

That level of lead (9ppm) is getting a bit too high for my liking, I guess having it drop to 4ppm is better. Was there anything during that run that may have caused increased bearing wear - running the oil too low, hard tracking event ?. Keep monitoring your oil going forward and see how it trends. Some of the current reading of 4ppm lead could be residual from the previous run, hopefully it will continue to decrease on the next sample.