Mutul 300V 5W30 11.500km Audi S5 4.2 V8

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Aug 24, 2020
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Dear BITOG members, a kind hello from the Netherlands and my first post!

In my quest to find the best possible oil for my car I chose the Motul 300V 5W30 (whether the choice was good, is a separate discussion). Before, the car had Audi official dealer oil every year. As the car is a collector' item (how I see it) it didn't drive much but since this year I chose to use more frequently. To evaluate my choice of oil, I invested in a UOA from a respectable Dutch company. Here is my data:

The car:
2008 Audi S5 4.2L V8
29.000 km (oil in) 40.500 km (oil out)
No modifications, 100% original. Exclusively used 98 or 100 octane fuel.

The car is in pristine condition and no expenses are spared to keep it that way. I drive the car weekly and most distances are over >20 km. Occasionally I go for spirited drives and the last 4000 km have been from the Netherlands to Italy and back. The car hasn't (and never will) see track and it goes without saying it is warmed up gently.

The oil:
Motul 300V 5W30
Used for 11.500 km, from February '20 til August '20.
The sample was taken during the oil change. I requested to sample it halfway the 'stream' of oil coming out and collected it in a sterile container.

The oil analysis:
(see attachment). Anyone who can help me out to make it instantly visible?

The conclusions from the UOA:

Positive:
1) Oil TBN is good, no big decline from 7.97 to 6.8 (TAN is 3.58)
2) Viscocity is good, from 11.0 to 11.34, a slight thickening
3) No metals, engine wear nonexistent

Remark:
4) Some silicon might indicate change of air filter is advisable

Worrying:
5) Flash point has dropped significantly from 232°C / 449.6°F down to 160c / 320 F. Presumably due to fuel dillution.

I used this UOA of a virgin 300V 5W40 to compare:

I used the closest resembling car/engine to mine to compare:
Audi S4: https://www.bobistheoilguy.com/forums/threads/05-audi-s4-motul-300v-5w30-5150-oci-67k.174046/

And I used the following to compare:
Honda S2000: https://www.bobistheoilguy.com/forums/threads/motul-300v-5w30-4000-interval-40k-mi-s2000.121468/
Subaru BRZ: https://www.bobistheoilguy.com/forums/threads/motul-300v-5w40-5000km-60000km-odo-subaru-brz.261524/

Looking at my own data first, most seems well, especially for a 11.500 km interval for this oil, underlining its applicability for street use as TBN and viscosity seem in good range. However the flash point is interesting and a bit worrying. Obviously excessive fuel seems the first cause to think of (too rich mixture, leakage?) but I do wonder if there could be an other cause. Also considering that the car did a high speed run to Italy and back, all fuel should have been evaporated if there was any to evaporate. So to me (and I am no expert, I hope you all are) it seems a possiblity that the oil doesn't hold its flash point well enough with my car, my use and my climate... I guess. As mentioned, the car runs perfect and is the same state it left the factory as if it was yesterday. I highly doubt the ECU is overmixing or the lambda is not feeding correct values but I cannot exclude it as a cause either.

So, I am VERY interested in your thoughts!
a) What could be the cause of the significantly lower flash point?
b) What is the cause, of this cause? :) I.e. if it's fuel dilution, how could it have happened?
c) Any other UOA of Motul 300V that show similar drop in flash point?
d) What would you consider a minimum for the flash point? 200c?
e) Anyone knows of any 4.2L V8's (Audi) UOA and specifically Motul 300V?
e) Other remarks and opinions!

PS. I phone with Motul Germany, technical dept. but they couldn't provide me with an answer. The asked me to mail them the analysis, which I did but I haven't heard back (yet?).
 

Attachments

  • 637330123723605266.NLRDMJ20210025-001_Lub Oil_Sample as received___Analysis_Bureau Veritas Lab...PDF
    557.2 KB · Views: 269
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First off, welcome to the forum I hope you enjoy it here and gain vast knowledge.

As for the oil? ****, never seen a long interval on the 300v as many don't classify it has that. I would drain it out at 5000km for my car as many see this as a "race oil" rather than a daily driver oil. None the less things look good. As for the questions:

A: Could be the oils chemical composition that keeps FP strong is fading out could be wrong though
B: it COULD be fuel dilution but I want others to chime in
C: Haven't seen
D: I'd say 200 is expected
E: Sadly I do not
F: Great detail in your first post you'll be getting some better replies soon.
 
Considering the interval, I think the oil did pretty good.

Aren't these engines prone to fuel dilution? How did the oil smell? Any way to have fuel content measured next time?
 
I want the best possible oil... and then we don't use one that has the required approval for the engine? I just don't understand.

The proper answer from Motul should have been that you're using the wrong product in your application.
 
Wasn't there a RLI oil developped for these engines, with copper as friction modifier?
Not aware of it. As far as I know, people would usually run thick 5W40. Though I have seen UOA with thick W30 that have good results such as Edge 0W30.
Now, most people run OCI of 5,000 miles in these engines.
 
Thank you all for your replies.

- As far as I know the engine is not a 'fuel dillution monster' unless something is off. So I doubt that is the cause.
- Not sure what an RLI is and don't know about oils with copper as fm added..

With regard to 'long use'. Before running this OCI I discussed this with Motul who explicitly stated an OCI of 10-13.000 km would be fine for the oil. Their claim was that there is sufficient additives to allow for such a use. However in my application, it seems not so for the Flashpoint but does confirm other properties for long use (visco, TBN).

My next question would be.. what is so bad about low Flashpoint? Obviously it would create a hazardous situation if it were to drop below 150 and vapors would start igniting. But are there any other hazards to think of?
 
My guess is just fuel dilution. TBN of the Motul oil should be sufficient for a ~10000Km OCI, especially with Europe fuel. Can you have the fuel content of the oil analyzed next time?

In any case, I still think the oil did well, I would stick to a 10000Km OCI next time. Motul 300V gave the smoothest running to all cars I tried it in. Never tried Redline though.
 
11.34 cSt @ 100C
Flashpoint B]

Those are not numbers I'm used to seeing together for a 5W-30 Synthetic. I'm a little dubious that both are correct. If they still have a sample and can run a Fuel Dilution Test it would be helpful.
 
Another thought, could it be that the lab just doesn't bother with flashpoint test? <160°C doesn't strike as a precise measurement. Do you have other reports from that lab you can compare to?
 
11.34 cSt @ 100C
Flashpoint B]

Those are not numbers I'm used to seeing together for a 5W-30 Synthetic. I'm a little dubious that both are correct. If they still have a sample and can run a Fuel Dilution Test it would be helpful.

And this is not any synthetic oil. It is designed for racing applications.
 
My guess is just fuel dilution. TBN of the Motul oil should be sufficient for a ~10000Km OCI, especially with Europe fuel. Can you have the fuel content of the oil analyzed next time?

In any case, I still think the oil did well, I would stick to a 10000Km OCI next time. Motul 300V gave the smoothest running to all cars I tried it in. Never tried Redline though.
Per Motul this is not street oil and should not be used in regular driving regimes. Just because it runs smooth does not mean it is good for every day.
There are oils that could be used both on street and track. Motul makes 5W40 Sport which is API SN. Mobil1 advertises 0W40 FS as racing applicable, and sells 15W50 as racing applicable while it meets ACE A3, API SN.
 
And this is not any synthetic oil. It is designed for racing applications.
That certainly reflects poorly on your opinion of Motul if you are suggesting they just picked the 13,000 km number out of thin air and did no testing to support that during development.

I personally have a higher opinion of them than that and haven't noticed low Flashpoint after use being a characteristic of Motul Racing Products before. It is possible it's heavily oxidized and the thickening is masking the amount of dilution which is why I suggested a fuel dilution test. Still in a true Synthetic that seems unlikely at only 7,000 miles even if the detergent - dispersion package isn't particularly robust.
 
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That certainly reflects poorly on your opinion of Motul if you believe they just picked the 13,000 km number out of thin air and did no testing to support that during development.

I personally have a higher opinion of them than that.

PS I haven't noticed low Flashpoint after use being a characteristic of Motul Racing Products before.
No I was not referring too Motul as bad oil. Look, Motul clearly states that this is racing oil, intended for short distance races, rally etc. <y point is, prolonged OCI, daily driving is not what this oil is made for, and this low flashpoint might be symptom of that use.
 
No I was not referring too Motul as bad oil. Look, Motul clearly states that this is racing oil, intended for short distance races, rally etc.
According to the OP Motul told him it was good for 10,000 - 13,000 OCI. Which by European standards is a short OCI. Motul recommends 300V for 5,000 km in race use and 8,000 km in street use in a 14,500 rpm motorcycle engine. I honestly haven't kept up with their auto recommendation for street use.
 
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Per Motul this is not street oil and should not be used in regular driving regimes. Just because it runs smooth does not mean it is good for every day.
There are oils that could be used both on street and track. Motul makes 5W40 Sport which is API SN. Mobil1 advertises 0W40 FS as racing applicable, and sells 15W50 as racing applicable while it meets ACE A3, API SN.
That's not what they say when you call them. I was told several times 300V is fine for street use too (but yeah, I read their doc and it's nowhere in there). I'm sure the 300V is much more ordinary than what many believe, and it's just "a** covering" in their official communication. After all, it has absolutely no certifications. That, or most Motul rep don't know what they are talking about...very possible :LOL:
It's smooth probably because it's loaded in moly and other friction modifiers, but as per some comments above about possible thickening, it's very possible they are not advertising it for street use (would also make their other lines appear like "lesser oils") is because it can't stand the European long OCI. And advertising like so would make it good "less good".
IMO, considering the "real" price of the 300V compared to the rest of the Motul lineup (I'm not talking inflated prices we see often, but French prices at a non greedy distributor), it's not surprising.
 
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That's not what they say when you call them. I was told several times 300V is fine for street use too (but yeah, I read their doc and it's nowhere in there). I'm sure the 300V is much more ordinary than what many believe, and it's just "a** covering" in their official communication. After all, it has absolutely no certifications. That, or most Motul rep don't know what they are talking about...very possible :LOL:
It's smooth probably because it's loaded in moly and other friction modifiers, but as per some comments above about possible thickening, it's very possible they are not advertising it for street use (would also make their other lines appear like "lesser oils") is because it can't stand the European long OCI. And advertising like so would make it good "less good".
IMO, considering the "real" price of the 300V compared to the rest of the Motul lineup (I'm not talking inflated prices we see often, but French prices at a non greedy distributor), it's not surprising.
I am going with it that no company that makes strictly racing oil, advertises as street applicable. Mobil1 clearly states that their racing oils 0W30 and 0W50 should not be used, and if oil is intended to be used on street and racing, to go Mobil1 0W40 FS and 15W50.
Motul has oil that is both street and race, Sport oil. I think it is 5W40 and 5W50 and 5W40 goes I think on Amazon for $56 for 5ltr. It is also Ester based.
 
According to the OP Motul told him it was good for 10,000 - 13,000 OCI. Which by European standards is a short OCI. Motul recommends 300V for 5,000 km in race use and 8,000 km in street use in a 14,500 rpm motorcycle engine. I honestly haven't kept up with their auto recommendation for street use.
There is no such recommendation for 300V. I was looking at 300V for track in my BMW, but their Sport oil looks better for dual use.
 
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