That comes down to whether the engine is tuned for the higher octane fuel or not. Many European cars (at least) are tuned for 95 RON, and will retard the ignition timing (reducing power delivery) when the knock sensor detects detonation. In these cases, fuel economy and power will suffer.

On the other hand, if your car is not tuned for 95 RON or above you will notice no improvement in power or fuel efficiency as a result of using it.

Ethanol-blended fuels may well have a higher octane rating (e.g. Shell's 100 RON V-power MAX) but since ethanol contains less energy than petrol, power and economy will suffer even though the octane rating is higher.

_________________
Simon

The adventures of an owner builder in the Tallarook Ranges

Yer but think about it this way, it's 10% ethanol which has around 2/3 the energy of regular petrol so you sould use 3.33% more fuel to do the same trip. So if fuel is $1 a litre then it needs to be around 3 cents a litre cheaper to break even, at $1.50 a litre it needs to be about 5 cents a litre less. With the price of fuel now is it really cheaper to run on E10?

_________________
The 850 Man

Not really, but soon you will have NO choice anyway unless you use 95 or 98. Shell has made 10% ethanol compulsory now in all 91 octane, I bet BP & the others won't be far behind.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I used the SAFF (I think it's now called EnvFFuels or something now) 98 octane ethanol blend petrol for over 2 years in my Mini without a problem. It's really not all that bad.

The only reason why I changed to using other petrol was the SAFF fuel station became a Liberty and didn't offer 98 octane anymore so I had to drive to the Shell to get 98. The SAFF was great, the blokes there would fuel the car up for ya! But it's no good if the car pings all the way home.

edit: Actually if shell V-power is an ethanol blend too, then I've been using it for 4 years without a problem.

_________________
1964 Morris 850, 1330 Supercharged - 81.8hp atws.
1975 Leyland Mini S 1100S powered - Nice and reliable.
1977 Leyland Mini LS - Project LS-T

Regular V-power 98 has no ethanol. Their 100 RON V-power Max has either 5% or 10% ethanol.

_________________
Simon

The adventures of an owner builder in the Tallarook Ranges

Partly OT, but does anyone know why I can run 91 - 98 octane in my mini without pinging at all, but the car seems to have more power and rev easier the higher the octane. Also, the higher the octane, the lesser the engine braking.

The last time the mechanic tuned my car, I think it had 98 in it, if that helps.

_________________
Copper 4 lyfe!

Expect to see more servos out of fuel with this roll out of E10.

Supply will not meet demand.