Lexus's hybrid IS

IT was celebration time for Lexus in Detroit – and Toyota’s luxury arm marked its 20th birthday with the launch of a new petrol-electric hybrid.

Called the HS250h, the executive saloon is slightly shorter than the IS. It features a 184bhp 2.4-litre petrol engine, which is linked to Toyota’s latest petrol-electric drivetrain.

While there isn’t any official fuel efficiency data yet, the eco-friendly machine is said to return even better figures than a Smart ForTwo around town – so expect at least 50mpg.

It should impress just as much beyond the city limits, thanks to a super-slippery body that results in a drag coefficient of 0.27 and CO2 emissions of around 100g/km. Unfortunately, the HS250h is aimed at the US market, and there are no plans to bring it here. However, Lexus hopes to launch a hybrid version of the IS, and the technology from the HS250h is likely to underpin the new car, which should arrive in 2010.

In the meantime, the firm’s latest RX450h SUV goes on sale this year, as part of Lexus’s aim to introduce 10 hybrid models worldwide before the end of the decade.