2010 Toyota Prius

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What is it?
2010 Toyota Prius

What's special about it?
We've imagined the 2010 Toyota Prius with cutting-edge lithium-ion batteries and plug-in capability, and now the real thing is here at the 2009 Detroit Auto Show. And although the production version of the 2010 Toyota Prius isn't radically different from the second-generation Prius, it should bring some significant upgrades when it goes on sale in late spring 2009.

The most obvious of these is the adoption of a larger-displacement, 1.8-liter inline-4 engine with variable valve timing (intake valves only). Running on the Atkinson cycle, the engine makes 98 horsepower at 5,200 rpm and 105 pound-feet of torque — a big increase from the 76 hp and 82 lb-ft supplied by the second-generation car's 1.5-liter engine. The 1.8-liter uses cooled exhaust gas recirculation to enhance fuel economy (reintroducing cooled gas back into the intake manifold reduces pumping losses), and an electrically driven water pump eliminates the need for a power-robbing serpentine belt.

Toyota says total system power for the 2010 Toyota Prius is 134 hp, meaning that an additional 36 hp is coming from the car's nickel-metal hydride battery pack. The 2009 Prius had a battery pack rated for 28 hp.

The front transaxle that houses the car's electric motors and planetary continuously variable transmission is lighter this year, and Toyota says this reduces torque losses by up to 20 percent. An improved cooling system for the inverter allowed Toyota's engineers to make it smaller and lighter, too.

The upshot of all this is that the 2010 Toyota Prius will now hit 60 mph in 9.8 seconds, according to Toyota. That's a half-second quicker than the 2009 Prius and a full second quicker than the 2009 Honda Insight. The third-generation Prius is also more fuel-efficient, as Toyota predicts a 50-mpg combined EPA rating, versus the 2009 model's 46-mpg combined rating. By comparison, the 2009 Insight has a 41-mpg combined rating. Power, Eco and EV driving modes will let 2010 Prius owners prioritize getting to work on time or saving the planet by driving 5 mph under the speed limit.

Just as significant to us is the all-new chassis underneath the 2010 Toyota Prius. The wheelbase isn't any longer, but we suspect the track is a bit wider, given that the hybrid is 0.8 inch wider across the shoulders. Toyota says its engineers added caster and revised the front antiroll bar and bushings to improve straight-line stability — never a strong point for the second-gen car.

Fifteen-inch wheels remains standard, but the tires are wider — P195/65R15 instead of P185/65R15. Optional 17-inch wheels and P215/45R17 tires are likely an appearance upgrade rather than a dynamic one. Braking should be improved with either tire package, as every 2010 Toyota Prius gets four-wheel disc brakes. There's also a new regenerative braking system, which provides even more regeneration than before, says Toyota.

Toyota has not disclosed curb weight, but the company notes that aluminum is used for the hood, rear hatch, front suspension arms and brake calipers, while the rocker panels, center pillar and roof reinforcement are made of high-tensile steel. Those measures should help keep weight in check, but bear in mind that there's also more sound insulation to reduce road noise.

There's a bit more space in the cabin of the 2010 Toyota Prius, which is 0.6 inch longer than its predecessor. A slimmer front-seat design provides more rear legroom, though Toyota has not disclosed how much. Also, a revised battery pack layout has resulted in a cargo area that's 2.2 inches wider and 0.4 inch longer.

As expected, the 2010 Toyota Prius is available with all sorts of technological gadgets that your typical systems analyst won't be able to resist. For starters, there's the Touch Tracer system, which uses touch sensors on the steering wheel controls to bring up corresponding images on the instrument panel and ultimately minimize the amount of time you spend looking away from the road.

Toyota is also promising a simplified version of the self-parking system already seen in the Lexus LS 460 and on European- and Japanese-spec versions of the second-generation Prius.

There's also an optional moonroof with solar panels that power a separate ventilation system. The all-electric system maintains a steady cabin temperature while your Prius is parked in the sun to minimize the use of air-conditioning when you return to the car.

Other new options include a radar-based dynamic cruise control system with an integrated lane departure warning system, the Pre-Collision system from the Lexus line, and Safety Connect, the new Toyota equivalent of OnStar. Dual knee airbags for front-seat passengers are new to the standard equipment list for 2010.

Inside Line says: Demand for the second-generation Toyota Prius hit an all-time low at the end of 2008, but we have a feeling a shiny, happy new Prius will cheer everyone up. — Erin Riches, Senior Editor