Bio-Ethanol fuels are certainly where the future of where our modern day fuels are going. Many modern unleaded fuels are now incorporating up to 10% Ethanol by volume, but we would consider these to still be essentially an unleaded racing fuel.
More fuels are now though are increasing this ratio to in excess of 15% ethanol by volume, which shift them into the class of a Bio-Ethanol fuel. The higher the ethanol content, the greater the ability for the fuel to cool down the combustion process with an inter-cooling effect, produce greater power especially with high compression ratio’s and boost levels.
Ethanol fuels of 85 or 98% are heavily used in circuit racing with great results. It is certainly, as far as a race fuel goes, one of the cheapest options for racers.
Whilst there is access to Pump Fuel E85, this is not blended to the same quality as drummed E85, and has variations in the Ethanol Concentration. This also may or may not be mixed with 98 Octane Petrol which can affect its ability to resist detonation and be a lower quality fuel.
The final item to take note is whether the Ethanol is Corn or Sugar based. Sugar based can leave residues and is a lower octane (Max 108 Octane) compared to Corn based (Max 116 Octane) and has no residues, thus not requiring any additives to counter this.