2010 Toyota Prius. Click image to enlarge
By Jim Kerr
2010 Toyota Prius
With more than one million Toyota Prius’ sold in the world since 1997, Toyota definitely has the lead in hybrid experience. Still, new technology is a hard sell, especially when it involves major vehicle systems such as powertrains. It takes a while before a critical mass of owners makes the technology accepted by all.
Stephen Beatty, Managing Director of Toyota Canada welcomes competitor’s hybrids into the marketplace because it adds credibility in the public eye to what Toyota has been offering in the Prius. He believes hybrids are an integrated and practical approach to providing solutions for increasing fuel costs. According to Beatty, hybrid research has also enabled the development of plug-in vehicles and a platform for fuel cell powered vehicles because much of the control systems, motor design and battery technology can be applied to these future vehicles.
While the distinctive profile of the new third generation 2010 Prius is similar to previous models, there are numerous changes in the vehicle to improve its fuel economy and handling. Some of the more subtle changes include the shape of the roofline, underfloor body cover and diffusers beneath the rear of the car which direct air for better high speed stability and reduced drag. The Prius now has a Coefficient of Drag (Cd) of only 0.25!
As well, other technologies also improve fuel economy: LED (light emitting diodes) headlamps are featured on the top of the line model and uses 17 per cent less power than HID (high intensity discharge) headlights. All trim levels receive distinctive LED taillights, which use 88 per cent less power than conventional bulbs. Both of these reduce electrical load on the engine so fuel economy increases.
The Prius new powertrain includes a 1.8-litre four-cylinder gas engine which is larger than last year’s, but more powerful and fuel efficient. An electric waterpump enables the computer to control coolant flow rates and there is no parasitic drag from a drive belt. With no need for a drive belt (AC and power steering are already electrically powered) the engine can be made more compact and lighter. In addition, the engine uses a heat exchanger on the exhaust system to recirculate normally wasted exhaust heat back into the engine coolant. This reduces engine warm-up time and provides additional heat for the passenger compartment. The gas engine utilizes an Atkinson Cycle design that keeps the intake valve open longer to reduce engine pumping losses. Although effective, it does reduce low rpm engine torque slightly but this is compensated for by the electric motors in the Hybrid Synergy Drive.