A version of Toyota’s Hybrid Synergy Drive hybrid system in the HS 250h combines a 147-horsepower, 2.4-liter four-cylinder Atkinson-cycle engine with a 40-horsepower electric motor system to produce 187 horsepower altogether. A power control unit manages to recharge the battery while decelerating or braking, or to deliver an electric assist when accelerating. As such, the HS 250h can accelerate to 60 mph in 8.4 seconds, according to Lexus. The EPA fuel economy ratings for the HS are 35 mpg city, 34 highway. TheCarConnection.com found those figures to be perhaps slightly optimistic, as they often are for hybrids. This editor saw about 30 mpg keeping with fast-moving Orange County traffic but reached a 46 mpg average in exceptionally gentle, controlled conditions on level roads.
The HS 250h doesn’t feel like a performance car, or even particularly perky, but it’s not sluggish either. Thanks to the gasoline engine’s torquey response, coupled with the electric motor’s instant torque, the HS feels responsive in the 20 to 60 mph range and cruises at higher speeds more confidently than the Prius (or the Camry Hybrid). The electric-assist steering has a quick ratio and actually conveys some feel of the road, but soft suspension tuning means that there’s plenty of lean (and nosedive when braking); overall the HS handles in an unexciting but safe way. A Touring Package includes sport suspension tuning and 18-inch alloys, firming up responses somewhat.
The 2010 Lexus HS 250h is tight and quiet inside, thanks to details like an acoustic windshield and triple-layer door seals, but engine noise is more present than some buyers will expect in a Lexus. Any even moderate press on the accelerator is met, after slight delay, with a surprisingly vocal drone; we’re surprised Lexus didn’t work more to mute the gasoline engine’s coarse character. The real Achilles Heel of the HS250h seems to be its roofline; versus the Prius, the sedan loses a little bit of headroom in front and a lot in back. In front, the seats are mounted quite high and tall drivers such as this one can’t lower them enough, while in the back seat, the HS doesn’t feel as roomy as a Camry due to the restricted headroom. Trunk space in the HS 250h is vast; official capacity is 12.1 cubic feet, but it somehow feels larger. For those who keep track in terms of golf bags, the HS will fit four of them. But those who expect a little more versatility will be disappointed; the HS lacks folding back seats—or even a pass-through—because of battery placement.