Soaring fuel prices have spurred US demand for hybrid petrol-electric vehicles. Sales of the Toyota Prius, the top-selling hybrid, reached 9,850 in August, more than double a year earlier. Toyota has sold 72,849 Priuses this year, up from 31,406 in January-August 2004.

Sales of Honda's smaller Civic hybrid more than trebled in August. Ford sold almost 1,400 petrol-electric versions of its Escape sport-utility vehicle even though it did not qualify for employee discounts available on most other models.