ive been buying avgas from the heliports for atleast 20 years and have ran it in every thing under the sun from drag bikes,dirt bikes,quads,hot rods ive owned etc.what i have noticed over a period of time it will leave deposits on the pistons and valves over a long period of time, it will get to the point where valves wont seat from all the deposits and also pitt the valve seat.i have run it straight and have mixed it with pump fuel depending on what octane/flash point im after.for the price difference in avgas and vp i run alot more avgas than i do vp fuel.