The US car market is heading for its worst year in more than a decade as Americans turn their backs on large, gas-guzzling vehicles, according to June sales data due out today.

The figures come as the big US carmakers scramble to adapt to the dramatic shift in demand to more fuel-efficient cars and crossover vehicles. Chrysler yesterday said it would close a US minivan assembly plant and cut one of two shifts at a pick-up truck site. Chrysler's move will result in 2,400 job losses at the plants, both in St Louis.