Fueldrum -
That’s no better than a typical family car
. It’s worse for the environment that a typical passenger aeroplane.
But,family cars vary. For example there is the Toyota Yaris and Honda Civic,then you have Jaguar V12 and the Chevy Silverado !!
Perhaps the family dirive a 1981 XD Falcon with a clagged 6 in it with white paint work and a fat orange pin stripe,complete with 'car bog and chicken wire' body repair which may add weight to the vehicle, hinder road performance and increase fuel and oil burn ?
Too many variables to consider, I think !