At the same time, some gas-only models have become very fuel efficient.

NPR: The Prius Rules Hybrids �� but Is Interest Falling?

It first flew in 1989 and went on to become the best selling 30-seater plane ever made - in part because it is very fuel efficient and has half the running costs of a regional jet.

BBC: Saab's 'special mission' aircraft searches for customers

Thanks to the efficient turbocharged, common-rail, direct fuel-injection diesel engine, the concept car is still very fuel-efficient.

ENGADGET: VW unveils CrossBlue plug-in SUV with iPad mini headrests and 85MPGe efficiency (eyes-on)

The one outlier is Avantair, which provides fractional ownership of a very fuel-efficient turboprop called the Piaggio Avanti.

FORBES: Anecdotes On The Economy