With more than one million Toyota Prius’ sold in the world since1997, Toyota definitely has the lead in hybrid experience. Still, newtechnology is a hard sell, especially when it involves major vehiclesystems such as powertrains. It takes a while before a critical mass ofowners makes the technology accepted by all.
Stephen Beatty, Managing Director of Toyota Canada welcomescompetitor’s hybrids into the marketplace because it adds credibilityin the public eye to what Toyota has been offering in the Prius. Hebelieves hybrids are an integrated and practical approach to providingsolutions for increasing fuel costs. According to Beatty, hybridresearch has also enabled the development of plug-in vehicles and aplatform for fuel cell powered vehicles because much of the controlsystems, motor design and battery technology can be applied to thesefuture vehicles.
While the distinctive profile of the new third generation 2010 Priusis similar to previous models, there are numerous changes in thevehicle to improve its fuel economy and handling. Some of the moresubtle changes include the shape of the roofline, underfloor body coverand diffusers beneath the rear of the car which direct air for betterhigh speed stability and reduced drag. The Prius now has a Coefficientof Drag (Cd) of only 0.25!
As well, other technologies also improve fuel economy: LED (lightemitting diodes) headlamps are featured on the top of the line modeland uses 17 per cent less power than HID (high intensity discharge)headlights. All trim levels receive distinctive LED taillights, whichuse 88 per cent less power than conventional bulbs. Both of thesereduce electrical load on the engine so fuel economy increases.
The Prius new powertrain includes a 1.8-litre four-cylinder gasengine which is larger than last year’s, but more powerful and fuelefficient. An electric waterpump enables the computer to controlcoolant flow rates and there is no parasitic drag from a drive belt.With no need for a drive belt (AC and power steering are alreadyelectrically powered) the engine can be made more compact and lighter.In addition, the engine uses a heat exchanger on the exhaust system torecirculate normally wasted exhaust heat back into the engine coolant.This reduces engine warm-up time and provides additional heat for thepassenger compartment. The gas engine utilizes an Atkinson Cycle designthat keeps the intake valve open longer to reduce engine pumpinglosses. Although effective, it does reduce low rpm engine torqueslightly but this is compensated for by the electric motors in theHybrid Synergy Drive.
The Hybrid Synergy Drive concept of using two electric motors and aplanetary gearset to produce a continuously variable gear ratio in thetransmission as well as drive the vehicle has remained unchanged, butevery major part has been redesigned. The motor/generator units are 33per cent lighter but produce 20 per cent more power. The CVT now has agear reduction system in the planetary gear setup and the battery issmaller and lighter. Combined with the gas engine, the 2010 Priusproduces 22 per cent more power yet is seven per cent more fuelefficient than the 2009 model.
Some of that fuel economy comes from the redesigned control system.Drivers can now operate soley in electric mode for up to two kilometresif the battery is charged. An ECO mode changes throttle tip-in andtransmission ratios. The vehicle accelerates noticeably slower but fullpower is still available if the throttle pedal is pushed further. APower mode is also available for those days when you feel a little moresporty or you just want to impress the friends with what a hybrid cando. All of this is accompanied by new dash displays for Power mode andfuel economy that help you decide how to drive.
While many will buy the Prius for fuel economy, it can also beequipped with some very advanced technology for passenger convenienceand comfort. Intelligent Parking Assist, first offered on the Lexus LSsedans, will detect the parking space and automatically control thesteering to back the car into the stall. Dynamic cruise control andpre-collision warning and automatic braking use radar to sense vehiclesahead. A solar cell roof panel provides power to automatically vent theinterior of hot air on sunny days and remote air conditioning uses thekey fob to activate the electric AC system so you can cool the carbefore entering it.
These are only a few of the advanced technologies in the 2010 Prius.Their contribution to real-world driving ease and practicality shows usthat Toyota can make accepting new technology a lot less difficult. |
發表於 2009-7-26 10:34 AM
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