Best Engineering From Toyota - Prius

A decade ago, it was hailed as the car of the future. Today, the Toyota Prius defines the gasoline-electric hybrid genre, and is the benchmark against which every other hybrid is compared. And if the majority of cars sold are not hybrids – yet — hybrids are no longer merely vehicles for the high-tech fringe. Welcome to the future, or at least the beginning thereof.

And, for model year 2010, welcome to the next generation of Prius. It’s quieter, roomier, and more fuel-efficient that its predecessors. It also offers improved performance and a higher level of standard and optional equipment, including such over-the-top luxuries as a solar-powered ventilation system and Intelligent Park Assist self-parking. It’s cleaner than ever, and is built with processes and technologies that reduce its environmental footprint at every stage from construction through driving and to on final disposal.
Efficiency has been increased in mechanical and electrical/electronic systems and in aerodynamics. Although instantly identifiable as a Toyota Prius, just about everything — engine, hybrid drivetrain, chassis platform, body, and interior — is brand-new or significantly improved.
The key to both improved fuel efficiency and performance is an improved drivetrain. The new engine is larger, at 1.8 liters, and more powerful, with a maximum output of 98 horsepower. The Hybrid Synergy Drive system is 90 percent newly-developed, with reduced weight and improved power and efficiency with seamless operation. Before, it was easy to tell when the engine shut off or came back online as there was a noticeable jolt and throttle response could be uneven. No longer – the Prius feels electric-smooth all of the time. Combined maximum power output is up significantly at 134 hp, meaning that the engine and motor don’t have to work as hard at any given speed, which means less fuel used.
Attention to weight also helps, and so aluminum is used for the hood and rear hatch, and for some front suspension components. High-tensile steel is used for inner rocker panels, the central pillars, and for roof reinforcement. Despite a slightly larger size and increased use of sound insulation and vibration-damping materials, weight has only increased by about 150 pounds.
There is one model of 2010 Prius, available in four standard equipment packages with increasing equipment levels. Even the most basic has, among other things, a tilt-and-telescope-adjustable steering wheel with auxiliary audio and climate controls and “Touch Tracer Display”, a multi-information display/trip computer, air conditioning with an electric compressor to uncouple it from the engine, pushbutton start/stop, cruise control, full adjustability for the driver’s seat, a 60/40 split rear seatback, XM-ready AM/FM/single CD or MP3CD/auxiliary jack audio, and multiple driving modes: normal, Eco, Power, and EV. So no sacrifices need to be made. If you want or need more, it’s available — navigation system, upgraded audio, solar roof, and even a Lexus-level package with nav, the Pre-Collision System, Dynamic Radar Cruise Control, Lane Keep Assist, and Intelligent Park Assist.
I’ve just spent a week with a new Prius with the Solar Roof Package. Serendipity, or just plain luck, that was a week of triple-digit heat. Once I figured out how to set the systems (read the manual), the car could be pleasantly cool after sitting in the sun unattended. That’s all very well, but the best news is that the car itself is significantly improved. Disclosure: I’m an old-school mechanical person, and have not previously liked hybrids because of their sometimes-inconsistent throttle response. Note that “previously”. No such problem here (or in any new Toyota/Lexus hybrid). Without peeking at the informative display it’s nearly impossible to tell the power source at any given time – gasoline, electric, or a combination – and in reality that doesn’t matter. And where previous hybrid EPA estimates were at least a little optimistic, the new 51 city, 48 highway, 50 overall is spot-on as far as I can tell. I got 50, in mostly highway driving, and with little regard to maximizing fuel economy until the last gallon was left in the rather small 11.9 gallon tank. But that *was* 500 miles into the tank, so no complaint, really.
APPEARANCE: Form follows function as modifications to the second-generation Prius’s iconic shape are as much for decreased aerodynamic drag as for pure style. Its coefficient of aerodynamic drag is 0.25, the lowest of any production car. The windshield is even more sloped than before, giving an almost single-arch profile in side view. The headlights are more bulbous, and the vertical taillights are even larger and more prominent. Small windows below the thick windshield pillars improve forward quarter vision. Plastic plates over the aluminum alloy wheels add protection against minor curb scrapes, a good feature.
COMFORT: It’s easy being green in a new Prius. No sacrifices of comfort need to be made, there is plenty of useful space for passengers and cargo, with excellent climate control and good audio standard and just about any high-tech option is available. Interior styling has been revamped along the lines of the exterior – form follows function. As before, the main instrument cluster is offset to the center of the car, at the base of the windshield. The shift lever is no longer on the dash, it’s now on a high flying buttress console that has an open storage tray at floor level. My test car had leather seats, with the driver’s adjustable for cushion height in addition to all the usual parameters. Front seat comfort is very good, ditto for the rear, which gets more knee room courtesy of the new front seat design. Dual gloveboxes and the open console space (and a moderate regular console box with the auxiliary jack and power points) more than make up for a lack of door pockets, although the doors do have water bottle holders. Luggage versatility is helped by the 60/40 folding rear seat, and there is some hidden storage under the rear load floor, above the space-saver spare tire.
SAFETY: The 2010 Prius is designed and built to meet all safety requirements in all markets in which it is sold, and also to meet ever stricter future standards. It features front, front seat side, and full-length side curtain airbags, and a driver’s knee airbag. Active headrests in the front seats reduce the possibility of whiplash. Four-wheel antilock disc brakes with Electronic Brake Distribution, Brake Assist, electronic traction control (TRAC) and Vehicle Stability Control are all standard. Dynamic Radar Cruise Control, Lane Keep Assist, and the Pre-Collision System are available.
RIDE AND HANDLING: A new platform underlies the 2010 Prius, giving it improved ride and handling characteristics, a quieter driving experience, and greater collision safety. As before the suspension uses MacPherson struts in front and a torsion beam axle at the rear, but changes in geometry and bushing materials make for a better driving experience. It’s moderately soft, but not excessively so, and reacts directly to driver inputs. The electrically-assisted steering lacks road feel, which can make driving a Prius seem a bit like playing a video game — which may be appropriate, come to think of it… Brakes are now four-wheel discs, and are further improved by regenerative braking. In everyday use, you can’t tell that a Prius is anything other than a quiet midsized sedan.
PERFORMANCE: More power and better fuel economy? That shouldn’t be too much of a surprise, as a larger engine that doesn’t work as hard as a smaller one can be more efficient. “Larger” here is relative, as the new Prius prime mover is only 1.8 liters, up from 1.5. It’s still an Atkinson Cycle engine, for improved efficiency, and makes a maximum of 98 horsepower at 5200 rpm, with 105 lb-ft of torque at 4000 rpm. The electric motor has a maximum output of 80 horsepower and 153 lb-ft. Engine and motor revs are really irrelevant, as the split between power sources is determined by the Hybrid Synergy Drive computer, and the car can operate under gasoline or electric power, or a combination. Maximum combined output is now 134 hp, considerably better than the old 106. Changes to the inverter, motor, and CVT transaxle have reduced weight and size, and more importantly have made for smoother operation and lower fuel consumption. Driver-selectable Eco, Power, and EV modes are new this year. Power re-maps throttle response so less throttle travel means more response; Eco appears to do the opposite. With the EV button pushed and the battery charged adequately, the Prius can operate as an electric vehicle for about a mile at speeds under 25 mph. Acceleration is noticeably better, as is fuel economy. I never felt the new Prius to be underpowered, and 50 mpg was easily attained.