Unleaded or Super Unleaded?

[YamCam62]

I had read it was better for your engine! I had filled up with it last time, tonight I filled up with plain Unleaded, don't notice much difference really.
Thanks for your opinions

cheers, Rob

[johnp]

I researched this a few years ago running my bike on unleaded and then on super unleaded. I did a 300 mile test on each fuel and the only difference was that super unleaded made the engine run smoother. It did not give any more performance of economy. So save your money and stick to regular unleaded.

[Bluebottle]

As far as I understand it you would need a serious performance engine (race prep/Ferrari) to get the benefits

What Car magazine commisioned a study and found the benefits were more than wiped out by the cost at the pump, all the independent studies I have seen said the same.

[Drago]

Best way to look at it is your bike/car/vehicles compression ratio. All the octane rating of fuel basically
indicaties is how much compression the fuel can withstand before detonating. So if you have a low
compression engine then low octane fuel will be fine. If you have a high compression/performance
engine then it would need higher octane fuel. If your fuel octane is to low then your engine will be
more prone to knocking (and it will have less power).

Another thing is higher octane fuel doesn't mean more power, power comes from the energy density of fuel.
higher octane fuels do not have more hydrocarbons & oxygen than lower octane counterparts. So thats probably
why most people don't see a (noticeable) performance increase from the higher octane fuel.

Personally i'd stick to 95 fuel. (unless idiot's are panic buying and only super is left). If I had a vehicle with a
compression ratio of 12:1 or higher i would probably use higher fuel. But for now with both bikes at 10.5:1
compression ratio's 95 will do for me.

Wikipedia link on octane rating...

http://en.wikipedia.org/wiki/Octane_rat ... ne_ratings

[YamCam62]

Thanks folks and thanks for the link Drago

[Normsthename]

One other downfall of using Super might be reduced fuel consumption.
I have kept a detailed record of the fuel consumption of my 'Ickle car.
When running it on super Unleaded it actually does 4mpg less to the gallon, it does run slightly better on Super.

Andy

[barryG]

I accidently filled my old 1996 MR2 with 91 octane fuel in Germany, after a few miles the car started pinking like mad uphill and was down on power till I filled up again with real petrol

[Gio]

I tend to use Shell V-Power in my 2000 Burgman, not because of the higher octane rating buy because of the claimed inlet port cleaning from the extra detergents. Anyone who has stripped a used petrol engine down (carb or inlet injection) will have noticed the hard black coke like carbon deposit on the back of the inlet valve head and stem. Shell claim to prevent that building up and get rid of any existing deposit with regular V-Power use. The deposit restricts airflow into the cylinder hence lowering performance over time.
When I next check the valve clearances, I intend to remove the carb and have a peep down the inlet manifold to see if it is gummed up or nice and clean as Shell claim.

Perhaps someone has already done that and can comment on their findings ?

[Waldorf]

I'm certain that my truck ran better on Esso diesel than on other brands.
It may be that a particular 'named' brand of fuel does suit one particular engine.
I'm not a scientist so I couldn't prove it one way or another.

[YamCam62]

I tend to use Shell V-Power in my 2000 Burgman, not because of the higher octane rating buy because of the claimed inlet port cleaning from the extra detergents.

That was what I was told that Super Unleaded would do, as I said in my post, I was more interested in the benefits to the engine rather than performance / price etc, thanks for the input.

cheers, Rob