One of general aviation’s worst characteristics is that it’s not very environment-friendly. Putting aside (please!) the continued presence of lead in the vast majority of aviation gasoline, the typical aircraft piston engine is neither fuel-efficient nor clean-burning. That’s what happens when powerplants that haven’t fundamentally changed since before WWII are pressed into service for their second century. There are a lot of reasons for that, not least of which are certification costs and liability, but the fact remains that the engines many of us fly behind or between would have been banned from U.S.-manufactured automobiles more than 50 years ago.
There are many signs this is changing. For one, engines from manufacturers like Rotax and Jabiru feature fuel-efficient and cleaner-burning technologies like computerized fuel injection and electronic ignition. Compression-ignition powerplants (e.g., diesels) also typically burn cleaner and use less fuel for the same output. While diesels remain a small proportion of piston powerplants in the U.S., they’re not overseas, where 100LL availability can be spotty and Jet A abundant.
