In terms of usage per distance or usage per hour? I’m pretty sure alot of airplanes exceed some cars in the former. But some modern homebuilt experimental aircraft with electronic fuel injection and electronic ignition equipped engines could exceed cars in both the former and later.
The FAA approved Lycoming engines in the common Cessna is not designed for efficiency, but rather reliability. They’re gas guzzlers that use old technology. A couple companies like Diamond for example do have some pretty nice efficiency thanks to their use of ECUs.