Sunoco Ultra 94 / PC Ultra 94 (same thing) is "up to 10% ethanol by volume" I believe. Adding ethanol increases octane rating but as the ethanol content rises a larger volume is required to produce the same energy. I am not an engineer but I have heard no claims that ethanol burns and less (or more) cleaner than pure petroleum based fuel. The basic rule of thumb is higher octane fuels burn hotter and cleaner - period. So to answer your question I personally feel that you're best to stick with the 94.
Any gasoline engine will burn ethanol fuels including those with content higher than 10%. But of course their computers are not optimized to burn higher ethanol content fuels and as such fuel mixtures are not adjusted properly and as such can cause damage. Same concept as when I was a kid and accidentally filled the gas powered riding mower with diesel
. It still ran, the problem was shutting it off!
