THERE shouldn't be any problem in running your car on ethanol-blend petrol, as long as you understand it is still an unleaded petrol and needs the same sort of valve protection it needs on unleaded. The ethanol blends we are seeing are low in ethanol and there's generally no problem with them. It's only when you get to quite high blends that you could encounter problems. In terms of increasing fuel consumption, I don't know of any additive that will increase your fuel consumption on standard unleaded petrol.