I've been wondering what the performance difference is with Pure Gasoline(undiluted non-ethanol) versus 10% Ethanol or 'Standard' gasoline, namely in older cars. I have an 88' Suburban and can get pure gasoline for ~11% more than normal gas. I'm wondering: Is the pure better than the ethanol for my vehicle due to its age, or will it not make any difference? Would power be affected? How would MPG be affected? Would the pure gas be better for seals and other components, or is there no change? Does one type keep better over longer periods of time? Both 'Pure' and 'Standard' in this discussion are of 87 octane. Thanks.