Are more consumers basing their car buying decisions on their environmental awareness? Or are they merely seeking to save their pocketbooks from the rapidly rising price of fuel? Whatever the cause, more and more motorists are opting for hybrid drivetrains in their new vehicles, with sales of the fuel-saving technology at an all-time high in the U.S.

Registrations of hybrid vehicles in the U.S. rose a staggering 38% on levels just one year ago with a record 350,289 hybrids finding a home in the past 12 months. This only represents 2.2% of the U.S. market share for the year but levels remained positive throughout the period despite the market seeing an overall sales decline of 3%, reports the Associated Press.

According to industry experts it’s not just rising fuel prices that are driving hybrid sales. A record number of new hybrid models were also released onto the market in the past year including the new Nissan Altima, Saturn Aura and Lexus LS600h hybrid sedans and hybrid versions of the Chevrolet Tahoe, GMC Yukon and Mazda Tribute sport utility vehicles.

The Prius remained the best-selling hybrid in 2007, commanding 51% of the hybrid market, up from 43% in 2006 despite an influx of several new hybrid models.