what does it mean "Engine fuel Dilution LOW" on Motul 300v?

[tharoka]

Reasearching info about the 300v I found that in the Motul UK page it is displayed diferent oil dilution categories on the different grades:

0w20 LOW
5w30 LOW
5w40 MEDIUM
10w40 MEDIUM
15w50 MEDIUM TO HIGH
20w60 HIGH

How does affect the engine an oil with hi fuel dilution?
Does it mean that this are not the best oils for evereday use?
The 5w30 who is marked as LOW will be as LOW as other oils (i.e. Mobil1, GC,...)?

Thanks!

 

[Motorbike]

Fuel dillution for racing engines .

They are saying better not have much fuel in the 20wt .


The API should take note here

Or should it be the car makers allowing the use of 5w-20's for crazy reasons beyond me ? So double

 

[Motorbike]

Should I replace the word allowing with mandating ?

 

[tharoka]

Motorbike, apologize me but I can not understand you...

 

[Gary Allan]

quote:

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Should I replace the word allowing with mandating ?

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Tolerance, perhaps

 

[MGBV8]

The 20w60 high can be used for 24 hrs racing like Le Mans.

 

[moribundman]

0w20 LOW
5w30 LOW
5w40 MEDIUM
10w40 MEDIUM
15w50 MEDIUM TO HIGH
20w60 HIGH

tharoka, it means that a 0W-20 oil may not (I would like to say "will not") be safe to use if it gets diluted by fuel. A thicker oil can handle more fuel dilution.

I would never use an oil that can handle only "low" fuel dilution. That's too risky in my book, especially because my engine tends to run a tad rich.

 

[MGBV8]

As this is a race oil a few comparisons

Three Silkolene performance oils in a Honda Blackbird motorcycle. tfitted with a light, compact, naturally aspirated 1100cc engine which turns out 120+ bhp at the back wheel. The normal fill for this one-year-old engine was 15w-50, so the first reading was taken using a fresh sump-fill of this grade. (The dyno was set up for EEC horsepower, i.e. Pessimistic)

15w-50
Max Power 127.9 bhp @ 9750 rpm
Torque 75.8 ft-lbs @ 7300 rpm

After a flush-out and fill up with 5w-40 the readings were;

5w-40
Max Power 131.6 bhp @ 9750 rpm
Torque 77.7 ft-lbs @ 7400 rpm

0w-20 grade had already done a season’s racing with the Kawasaki World Superbike Team, giving them some useful extra power with no reliability problems. (But it must be said, they were only interested in 200 frantic miles before the engines went back to Japan)

0w-20
Max Power 134.4 bhp @ 9750 rpm
Torque 78.9 ft-lbs @ 7400 rpm

In other words, 3.7 bhp / 2.9% increase from 15w-50 to 5w-40, a 2.8 bhp / 2.1% increase from 5w-40 to 0w-20 or a 6.5 bhp / 5% overall. just for changing the oil! More to the point, a keen bike owner would have paid at least £1000 to see less improvement than this using the conventional approach of exhaust/intake mods, ignition re-mapping etc.

 

[tharoka]

Thank you very much moribundman, as you can see my English knowledge is limited.

Let me ask another question, why sould an engine oil be diluted by the fuel? When does it happen?

So the higher fuel dilution, the better oils is, isn´t it?

 

[cvl]

quote:

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Originally posted by tharoka:
So the higher fuel dilution, the better oils is, isn´t it?

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No. The higher the fuel dilution, the better the oil can handle fuel dilution. It shouldn't be a problem in a modern street-driven car, but 300V is also very popular with racers who do face fuel dilution issues sometimes. Unless you think that you're going to get more fuel dilution than the Kawasaki Superbike, you're fine with any of the weights.

 

[moribundman]

Ack!

[ September 23, 2004, 02:55 PM: Message edited by: moribundman ]

 

[moribundman]

quote:

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quote:

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Thank you very much moribundman, as you can see my English knowledge is limited.

Let me ask another question, why sould an engine oil be diluted by the fuel? When does it happen?

So the higher fuel dilution, the better oils is, isn´t it?

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The problem is not your English, the problem is that the chart is unclear.

The chart sounds like the use of thin oil (for example 0W-20) will result in low fuel dilution of the oil, while it really means that thin oil has only a low tolerance for fuel dilution. On the other hand, "20w-60 HIGH" means that this oil has a high tolerance for fuel dilution. If your engine has a problem with fuel dilution, you want to use an oil that can handle "high" fuel dilution.

Fuel dilution is a bad thing, as it thins the oil. A thicker oil can be diluted more with fuel without becoming dangerously thin. Fuel dilution happens when the engine runs rich: when the engine is not yet warm and at wide open or full throttle, basically whenever you step on the gas. Modern fuel injection minimizes fuel dilution, but at full throttle all engines run rich. Unburnt fuel will be scraped off by the rings and end up in the oil, thinning it.

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[ September 23, 2004, 03:01 PM: Message edited by: moribundman ]

 

[tharoka]

 

[Toyota18]

Thin oil not allowed much fuel dilution.0w-20 and 5w-30.
5w-40 and 10w-40 allowed little bit fuel dilution and 15w-50 no problem with fuel dilution at all.
I think Ester absorbe fuel.
Other street oils no problem with this.
ex; Mobil1.Motul 8100,
Or racing caused more to fuel dilute with oil than normal driving.thin oil limited allowed this than thicker oil.

[ September 27, 2004, 06:45 AM: Message edited by: Toyota18 ]

 

[dropitby]

I would never use an oil that can handle only "low" fuel dilution. That's too risky in my book, especially because my engine tends to run a tad rich. From what I read its not the oil that causes fuel dilution its more about engine operation such as stop & go driving idling thus if your fuel injection is ok you do a lot of highway driving your 5/20 or 0/20 will give you perhaps as good a #'s as the 10/30 or 5/40.I for one think you can improve your oil some by going with a synthetic blend or full synthetic. That alone will not make up for fuel dilution get the leak fixed or use a higher viscosity oil.

 

[outrun]

This string leads me to a long standing ponderance of mine.

OEM recomended 10W30 vs going with 5W30 & 0W30

Any comment how well 0W/5W30 can withstand fuel dilution (German Castrol, Mobil 1, Amsoil ASL & HDD)

Thanks I just found this aspect of viscosity vs fuel dilution tolerance fascinating.