"How corosive is this stuff for the fuel systems of not only our
Vipers, but also our daily drivers?"
Ethanol attracts water vapor and will eventually corrode a steel
tank - but using your car yearly should offset that.
In your DD the big issue is when you first start using it.
It will dissolve the rust and deposits accumilated over years in
your tank and flush it through the system all at once. Usually
this simply clogs your filter, but I have heard rumors of worse.
"Is it true your mpg will not be as good as with gasoline?"
Ethanol takes more heat to burn (which is why it's so awesome as
a race fuel) so in a normally tuned car expect a 3-5% decrease
in normal MPGs. On my Ram I have seen a real-world 6.9% drop.
"For those who store their Vipers, any negatives in using eth."
There are rumors of ethanol going "stale" after months of non-
use, but the seasonal additives applied to normal gas is more
likly to give you a headache. Summer gas and winter gas are not
the same! The owner of a local boat yard told me there were some
serious issues with long-term storage boats when the 10% was
first added, but have pretty much gone away now.
My car likes the non-ethanol stuff better than the blend (just a
feeling, no proof) my advice is to find the pure stuff if you
can, but you'll be fine if you cannot.