Hi iv always wanted a vintage tractor and recently the justification to get one has arisen iv done my homework learnt a thing or 2 to which one is best for my need but the perticular tractor I'm interested in is a 1949 American petrol powered unit my question is how do these engines fair running on modern day fuels is it doable with out damage to valves. Loss of power etc and what r the alternatives if modern ethonal fuels are not suitable would u buy a vintage tractor knowing it has been run on unleaded fuel any info much apriciated