Using Car Gas in Airplanes

My airplane came with an STC for car gas (also called mogas). For the first year or so I had the airplane, I used auto gas instead of avgas (aviation fuel) as much as possible. Car gas is about a dollar cheaper per gallon. Some people believe it’s also better for the engine, because it’s closer to the 80-octane fuel the engine was designed to use. Others disagree.

I used the lowest grade of major-brand, alcohol-free car gas available (87-octane unleaded). Most avgas sold today is 100-octane low lead (LL), although 80-octane is supposedly available in some areas. (I haven’t seen it yet.) I haven’t noticed any difference in performance between the two types of fuel.

In recent years I’ve been using avgas exclusively. The price almost always includes having the airport employees do the fueling. I can call ahead and have the airplane fueled and the cost charged to my account. It’s much less hassle than hauling jugs of car gas to the airport, especially now that I live a lot farther from the airport than I used to.

Also, many airports now have draconian rules that prevent or severely limit the owner’s right to fuel his own airplane, except at the gas pump. (A few airports have self-service pumps.)

A handful of airports still sell car gas for use in aircraft.

Jump ahead to Owner’s Log from 2003 or continue with the next post.