My jump into the ethanol conversation as it relates to those of us with older motor coaches or older tow vehicles running a carb based engine system or older early fuel injection systems. 

I have done a fair amount of air racing and aviation work as a pilot and we studied ethonol and its effects on an engine, Understand we may run a different engine layout but, its still an internal combustion engine much like a car. In fact my racing plane has an automotive converted engine. One of the two biggest concerns we came to was that ethanol based fuel , because they have a much lower BTU rating then regular gas, causes a severe air fuel ratio or A/F problem for any engine that does not have the correct valve train assembly but more important the correct systems such as a modern ECU or computer system that is able to read the specific A/F in-balance and reformulate the lean mixture and timing curves to compensate for the lower BTU rating of ethanol and the lower anti-knock which is typically 85 octane verses 87 octane or more of regular non ethanol fuel.Other than Flex fuel vehicles that were designed with fuel management capable of handling ethanol fuel, no engine not designed for this fuel should ever burn this fuel. Odd thing is, many states have pit laws into place requiring all fuel sold in their perspective state to have an ethanol blend. This is politicians and lobbyist at work doing what politicians do. making a law that is only following a money trail and not whats the best for the public. Unfortunately, many of you out there live in one of those states and have no choice in the fuel you buy. The long term effects on an engine not designed to use ethanol can be very devastating with everything from burnt valves and prematurely worn cylinder rings and the immediate effect of using it is about a 20% poorer fuel mpg. There are ways to convert an older engine to use ethanol and they are doing it in drag racing.  But, its also at a cost of much lower fuel economy and its pretty much a major cost of re-camming the engine and installing a EFI conversion system. I feel for you guys out there that are forced \ stuck with ethanol fuel.