Gas 95 in bike designed for 91. Any benefit?

[Maoser]

My CBR250 has 91 stickers on it and in the manual. I usually use 95 though. Sometimes E20 (95) but don't like 20% ethonal. Don't like any ethonal really, but there ya go. Is there any benefit at all of using 95 instead of 91? Cheers.

 

[Nightrider70]

It should not be any benefit. If you notice a benefit then the bike is either not properly designed for 91 or the fuel is not proper 91.

 

[brake034]

A bike designed for RON 91 will have a compression ratio suitable for that fuel, feeding a higher octane fuel does not have a huge influence on the performance of the bike.
Both gasohol RON 91 and 95 in Thailand have about 10% ethanol added to the gasoline, I am not sure if E20 reaches RON 95?
If the sticker does not mention E20, I suggest not to use it anymore!

If you do not like gasohol there is regular gasoline RON 95 available at most upcountry petrol stations as most agricultural machines do not like ethanol.
Each petrol company has a different name/color for it, so it needs a bit of discussing.

 

[brake034]

quote wiki: "A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power."
Link here> Octane rating - Wikipedia, the free encyclopedia

 

[bsacbob]

On the same topic sort of i was told if you plan to park your bike up for a while it would be better it was ls running on ron 95. Expecially if the bike was a carby and not Fi..

Sent from my SM-G900F using Tapatalk

 

[Maoser]

Cheers.

Sorry, it has 91 and E20 stickers on it and in the manual.

I left it sitting for a week once and came back and it has problems starting and spurtering. Never had it another time, my guess was that the ethanol had to some degree separated from the gasoline.


Will move to 91, unless it starts engine knocking etc with it.

 

[Loop]

Engines are designed to use the specified octane. A higher octane wont do anything except cost you more to fill up.

 

[brake034]

Gasohol 91 and 95 is a mix with 10% Ethanol in it. E20 is a mix with 20% Ethanol, E85 is a mix with 85% Ethanol, I believe pure Ethanol is around RON 106? The issue is that Ethanol is hygroscopic, it attracts and binds with water, causing a chewing gum like deposit.

So for a bike you want to put in storage, run it on (non gasohol) RON 95 for some time, top off the tank full and this should avoid the storage issues with Gasohol, or so they say.......

 

[schrauberklaus]

To my experience many Gasstations adulterate (is this the right word) the Gasoline together with all kind of crap to make more money.
Or its the Truck driver ,or the Distribution Station who knows.

My XL is set up with Shell V-Power , the time befor they add ethanol and Compression Ratio, Ignition Timing and advance curve , Carburators all near perfect for good gasoline.

So its very sensitiv to the Crap we get today . And i can feel and hear the difference between good (correct) 95 Gas and the Crap some Stations have in the Tanks.
What they write on the Pumps don't matter .
That the counter work for the owner is another thing . In Patong they fill once 9.8 L in a 2 gallon tank .

So if i can i pay the premium price for 95 Benzin , thats less likely to be mixed with other crap.

 

[Oddvar]

One of my bikes is a F6 cylinder with six carburettors. Very sensitive to the gasohol.
For some time it was hard to come by real Benzin before PTT started with 95 octane.
High temperatures, less power and less km pr litre was the result.
To avoid bad fuel I try to tank the bike at about half tank, in that way whatever I get will be halved.
I have also filled 20,1 litre in a 20 litre tank several times, even with the bike on the side stand.
I have filled the CRF250L to 7,7 litre as well.
I guess tank specification must be wrong from Honda. 555

 

[CraigBKK]

One of my bikes is a F6 cylinder with six carburettors. Very sensitive to the gasohol.
For some time it was hard to come by real Benzin before PTT started with 95 octane.
High temperatures, less power and less km pr litre was the result.
To avoid bad fuel I try to tank the bike at about half tank, in that way whatever I get will be halved.
I have also filled 20,1 litre in a 20 litre tank several times, even with the bike on the side stand.
I have filled the CRF250L to 7,7 litre as well.
I guess tank specification must be wrong from Honda. 555

On the Thai Honda website the CRF250's fuel tank is stated as 7.7L. A.P.Honda - Products "Power of fun project! - ???????????????????"