As stated aircraft engines hardest job is during take-off so its not a high altitude only fuel, 100ll is very clean and dry and probably qa better than race fuels, 100ll can be found in outside areas of big towns at smaller community airports were you can usually drive up to the pump insert your credit card and buy what you want and is usually couple dollars cheaper than the regional airports, we have it for 4.50/gal and the city airport is about 6.00+ i think you can google av gas prices in your area and it should show the airports around you who have it.