U. S. auto sales were pushed to their highest level in August in the past 15-month period owing to "cash-for-clunkers" program, which provided customers with $3,500 to $4,500 on swapping older vehicles for more fuel-efficient models.

In August car-manufacturers sold 1,261,977 cars plus trucks, up around 1 per cent as compared with the same period last year, the highest sales since May 2008. In July car-makers had sold about 997,824 units.

Sales at Ford Motor Co. soared by 17.2 per cent. Honda and Toyota reported an increase in sales of 9.9 per cent and 6.4 per cent respectively.

Comparatively smaller Asian auto-manufacturers, Subaru and Hyundai reported rise in sales of 51.5 per cent and 47 per cent respectively.

On the other hand, Chrysler LLC and General Motors posted a decline in sales. General Motors said its sales dropped 20.1 per cent in August, while Chrysler Group reported a plunge of 15.4 per cent in August sales.

More than 690,000 vehicles were scrapped in the US under the cash for clunkers program, in which consumers were benefited up to $4,500 and took advantage to drop gas-guzzling trucks and SUVs.

But, experts have warned that auto sales might take a dive in September.

Bob Carter, group VP for Toyota division, said, "While we still remain optimistic for a mild recovery in the auto industry in the fourth quarter, we do expect a drop-off in September."