Toyota Prius in a bigger and better package makes more power
Bob Plunkett
Date Posted: 5/10/2005
|
LITTLE ROCK, Ark. -- It only takes the blink of an eye to clearly see that Toyota's new second-generation design for the Prius four-door sedan, which is bigger and better than the original, looks different from any other vehicle on the lot at a Wal-Mart store in Little Rock, Ark.
In this new design, the overall profile of Prius, so sleek and streamlined and simple, features a dramatic sloped face that fashions the hood and windshield into a flat and racked-back plane.
There's an arching line to the roof extending over the expanded cabin before it tapers gradually through a hatchback-style rear lid and window to the abrupt crimp of the tail.
First impression for this new treatment of the exterior package makes Prius look like some Space-Age sled for the future built with exotic materials and capable perhaps of galactic speeds.
In fact, Prius is not a speed demon, although the new version exhibits a zippy personality that's a dramatic improvement over the first-generation model, which arrived in North America five years ago.
The important point is that this progressive design for Prius conceals a carload of sophisticated hardware and computerized electronic controls which enable it to operate like no other car on that Wal-Mart lot.
And, Prius in this design. with an aerodynamic rating of merely 0.26 cD (coefficient of Drag), scores as one of the slickest set of wheels in the world.
Consider it a hybrid gas-electric vehicle that earns significantly high fuel economy marks because it packs into its futuristic shell not one but two motors.
There's a thrifty but conventional 1.5-liter four-cylinder plant aboard that operates on gasoline plus a battery-powered electric motor of permanent-magnet design.
Toyota adds a new high-voltage and high-torque Hybrid Synergy Drive (HSD) system to control all energy produced by the two plants and apply it directly to the front wheels in infinitely variable measures through an electronically-controlled continuously variable transmission (CVT).
Prius in this new version can run on the gasoline engine or on the electric motor, or in a mode with both plants contributing power simultaneously.
Virtually silent at start-up with only the electric motor switching on, Prius will surge forward on command with initial help from the electric motor and the gasoline engine not actually firing up until the vehicle moves faster than three miles per hour.
At highway speeds the gas engine does most of the motivating, while in reverse gear it's the electric motor that handles all of the work.
The four-cylinder gasoline-fired plant, with dual overhead cams and Toyota's smart variable valve-timing (VVT-i) system, musters 76 hp at 5000 rpm plus torque of 85 lb-ft at 4200 rpm.
That's a boost of six power points over the four-cylinder engine in the original Prius.
The 500-volt electric motor, tied to a 201-volt nickel-metal hydride battery, makes 50 kilowatts of power (the equivalent of 67 hp), with torque amounting to 295 lb-ft available from zero to 1200 rpm.
Thanks to the addition of a high-voltage power converter, the new system generates about 50 percent more electric power than the previous motor and also provides more low-end torque to enhance acceleration.
It enables Prius to virtually leap off the line from a stop-light start, then zip quickly to cruising speed.
And, compared to the prior Prius, this new powertrain acts with far more force and feels like a conventional car outfitted with a strong engine.
Despite the boost in power, Prius in its new mode achieves even higher fuel economy figures -- ratings reach to 60 mpg for running on city streets for the class of a Super Ultra Low Emission Vehicle (SULEV).
In a switch from convention, Prius actually achieves better fuel efficiency when plowing city streets in start-and-stop traffic rather than when cruising at a swifter pace on a highway.
That's because its gas engine works at higher speeds, while in city traffic with frequent stops the electric motor takes over.
Power from the gasoline engine is utilized in two different ways. One portion of this energy is used to turn the front wheels, while another portion powers an electric generator that runs the electric motor, which in turn sends the supplemental power to the wheels.
Stomp the accelerator to romp into a passing lane and the electric motor adds an extra boost, yet for such a heavy demand of power the operating energy for the motor comes directly from a bank of on-board batteries.
Internal recharging occurs either during braking, when the gas engine operates as a generator, or when the electric generator does the recharging job. Thus, Prius never needs to be plugged in for recharging like a purely electric vehicle.
A video screen, centered high on the dashboard atop the central stack of audio and climate controls, illustrates operations for the energy management system with icons representing the gas engine, electric motor, drive wheels and battery. Arrows depict the energy flow, with one running from the engine or motor to the wheels when either plant supplies power, or another flowing back to the motor and on to the battery when recharging occurs.
It's fascinating to observe the intricate movement of these arrows, although as the driver you must be careful to keep eyes on the road instead of the video screen.
The cabin of Prius -- longer and broader and taller than the original thanks to a new platform with the wheelbase extended six inches -- moves up to the mid-size class and provides ample room for five passengers.
Driving Prius becomes a high-tech maneuver.
A remote transmitter fob takes the place of an ignition key, as the smart car will recognize a driver by the proximity of the transmitter. Simply slip into the bucket seat and punch the power button on the dash.
The electric motor switches on silently, as confirmed by a green light.
Then control the transmission through a dash-mounted joystick that's electronically linked, as is the throttle, the steering system, even the brakes.
Toyota maintains the MSRP of the former model at only $19,995, with a package of premium gear listing for $3,150.
|
| 2004 TOYOTA PRIUS VEHICLE SPECIFICATIONS |
| Description: |
Mid-size hybrid 5-door sedan
|
| Model Options: |
Mid-size hybrid 5-door sedan
|
| Wheelbase: |
106.3 inches
|
| Overall Length: |
175.0 inches
|
| Engine Size: |
DOHC 1.5-L I4 VVT-i
+
Magnet 50-kW Electric Motor
|
| Transmission: |
Electronic CVT
|
| Drive: |
Front
|
| Braking: |
Electronic disc/drum
ABS/EBD/TRAC
|
| Airbags: |
2 (front) + 2 (side)
|
| Gas Mileage: |
60/51 mpg
|
| MSRP Price: |
$ 19,995 |
|
|
|
The Big Lot! is dedicated to privacy, security, and service. Read our Privacy Policy.