But market watchers said the increases were modest, despite fewer COEs being available and the longer interval between yesterday's tender and the previous one.

The Government holds two tenders a month, with two weeks separating most exercises. But sometimes, because of the number of days in a month, the gap can be three weeks.

A longer interval would give car dealers more time to collect bookings, which usually translates into higher demand - and prices - for COEs.

With the smaller COE supply, premiums should have risen more than they have, motor traders said.

The supply of car COEs available between this month and March next year is 8.5 per cent smaller than the previous quota year. The number of commercial vehicle and motorcycle COEs shrank by 4.5 per cent and 2.9 per cent respectively.

Managing director Mark Choong of Toyota distributor Borneo Motors noted that fewer bids were submitted this time.

Results released by the Land Transport Authority showed that 5,743 bids were submitted for car and commercial vehicle COEs, down from 6,027 three weeks ago.

Motor traders said record fuel prices, wider Electronic Road Pricing (ERP) coverage and spikes in parking charges may be starting to dampen Singaporeans' appetite for cars.

This is evident even in the showroom for Toyota, Singapore's most popular brand. Mr Choong said those who were considering buying a car were 'thinking a bit more' before signing on the dotted line.

Nevertheless, with the smaller COE supply, bidders are expected to compete more aggressively for them.

Motor Traders Association president Michael Wong said he expects premiums to breach $20,000 - a level not seen since 2005 - 'probably by June'.

Buyers and sellers of small trucks would be hardest hit, he said, because the COEs would cost more than the vehicles themselves.

But other traders said buyers undeterred by rising usage costs will still find cars relatively affordable. Since the COE system started in 1990, car premiums have long hovered between $30,000 and $50,000. In 1994, it hit $110,000.

'Anything below $20,000 is cheap,' said Mr Barry Kan, general manager of Jaguar and Bentley agent Malayan Motors.

But more immediately, dealers are raising prices. Honda agent Kah Motor, for example, upped the prices of its cars by around $1,000 before yesterday's tender closed at 4pm.

christan@sph.com.sg