In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "normal" gasoline in the US and Canada, would be 91 in Europe.

The three vehicles averaged 1.5% lower mileage with E10, 2.2% lower mileage with E20, 5.1%

unless america has some crazy rotors driving around out there, i'll stick with my comments, and the reaserach is years of them offering ethanol in australia, as well as Mazdas specific instructions NOT to use ethanol blends in rotaries, they said the rx-8 should be ok on a 10% MAX blend, but no more, and no early rotaries should use ethanol blends except in the most extreme of times.

Maybe americas rx-7s were tuned for 91 octane, and can handle a little more abuse, but what i said is true, if it isn't tuned for it, it isn't good for it.


we normally have cars tuned to run on 98 fuel here, using a crappy ethanol blend WILL lean out the AF ratio, maybe it's different over there, but i doubt it

You are requested not to use gasahol more then 10% ethanol, or any gasahol containing methanol

Mazda Mazda 323 1.8L (1994 onwards), Mazda 323 2.0L (2001 onwards), Mazda2 (11/02 onwards), Mazda3 (All), Premacy (5/02 onwards), Mazda6 (8/02 onwards), 800M and Millenia (8/98 onwards), RX-8 (7/03 onwards), MPV (8/99 onwards), Tribute (All) and E-series (2002 fuel injected models onwards) vehicles will operate satisfactorily on E10. All other models not listed above do not operate satisfactorily on E10.

TECHNICAL REASONS FOR INABILITY TO USE E10
The following are reasons why certain vehicle models cannot or should not use E10 because of material incompatibility and driveability issues respectively. There are also comments on possible exhaust and evaporative emissions issues. This list was compiled from information submitted by manufacturers.

CANNOT USE BECAUSE OF MATERIAL INCOMPATIBILITY ISSUES

Early deterioration of components in fuel injection system:

Fuel tanks
Fuel lines/hoses
Injector seals
Delivery pipes
Fuel pump and regulator
Vehicles with carburettor fuel systems may experience hot fuel handling concerns and may experience a lower level of durability in some fuel system components.

Some manufacturers advise not to use E10 with any model equipped with a carburettor because of material incompatibility.

SHOULD NOT USE BECAUSE OF DRIVEABILITY ISSUES

Vapour pressure of fuel with ethanol will be greater (if not chemically adjusted) and probability of vapour lock or hot restartability problems will be increased.

Oxygen content of ethanol is 34.7%. This can cause the engine to run lean although the Engine Control Unit (ECU) can generally compensate via feedback from the O2 sensor under light throttle conditions. However, hesitation or flat-spots during acceleration can occur due to this lean-out effect.

Difficulty in starting and engine hesitation after cold start.

EXHAUST AND EVAPORATIVE EMISSION LEVELS

Lean-out resulting from the oxygenating effect of ethanol in the fuel may affect exhaust emissions.

Fuel containing ethanol can increase permeation emissions from fuel system components.

Vapour pressure of fuel with ethanol will be greater (if not chemically adjusted at the refining stage) and can lead to increased evaporative emissions.

We are going to have to face up to the fact that alternative fuel is something that needs to be given a GOOD HARD LOOK

Hydrogen is being analyzed as an alternative fuel, creating a hydrogen economy. Because hydrogen in its gaseous state takes up a very large volume when compared to other fuels, logistics becomes a difficult problem. One possible solution is to use ethanol to transport the hydrogen, then liberate the hydrogen from its associated carbon in a hydrogen reformer and feed the hydrogen into a fuel cell. Alternatively, some fuel cells (DEFC Direct-ethanol fuel cell) can be directly fed by ethanol or methanol. As of 2005, fuel cells are able to process methanol more efficiently than ethanol.