The latest car is packed with Toyota’s most modern technologies, including an all-new platform that will underpin other models.
FOR the past 18 years and across three model generations, the Prius has been the poster car for eco-motoring. The new fourthgeneration model is likely to stay on the same “poster”, thanks to even greener performance made possible by state-of-the-art hybrid technology.
But this time, Toyota has tried to make the Prius less geeky and more funky. When chief engineer Koji Toyoshima introduced the key points of the new car to the journos, “excellent fuel economy” was third on the list, after “fun to drive” and “eye-catching design”. The newcomer’s exterior design is quite a sight indeed.
There are hints of the radical Mirai (hydrogen fuel-cell Toyota) in the styling, that integrated rear spoiler is neat, and the red LEDs in the tail-lamps look dramatic when lit.
Dramatic, too, is how the dimensions and proportions have changed. The new car is 60mm longer, 15mm wider and 20mm lower than the old one, while the plunging roof profile, rising belt line and black C-pillars create a “teardrop” glasshouse. The nose of the vehicle is now so low (70mm closer to the ground) that its Toyota badge is at the same height as the one on the 86 sports coupe.
The car’s coeffi cient of drag has also been lowered to 0.24 – marginally better than the predecessor’s 0.25, but otherwise not much of an advantage outside a wind tunnel. Inside the cabin, both space and comfort have been improved, but the latter is more noticeable thanks to the well-cushioned seats, well-distributed airconditioning and the interior silence once you shut the doors. This is the quietest Prius yet, with little outside noise intruding from the windows, wing mirrors and fender areas. My ears tell me this Toyota “sounds” like the inside of the refined Lexus IS.
Credit goes to the tighter body structure of the Prius, with its greater proportion of high-strength steel and more laser-welded points, plus the addition of more noiseabsorbing/ insulating materials under the floorboard and around the dashboard. Mechanically, there are significant improvements to the proven 1.8-litre petrol-electric drivetrain.
The engine has a diesel-like thermal effi ciency (productive combustion relative to wasted heat) of 40 percent, up from 38.5 percent. Also, the mechanical loss of the hybrid transmission has been reduced by 20 percent, the high-output motor is 20 percent lighter, and the power control unit is over 30 percent smaller yet more efficient.
Furthermore, the nickel-metal hydride battery pack has been downsized (1kg lighter and 10 percent smaller), and its charging effi ciency has been boosted by almost 30 percent. The downsizing of the battery pack has allowed it to be repositioned from behind the backseat to under it, parked with the fuel tank. Coupled with a boot floor lowered by 110mm, its liftback cargo capacity has been increased by 56 litres to a useful 502 litres – more than the current Corolla Altis notchback.
Interestingly, there’s a version of the Prius with a lithium-ion battery pack, which saves an additional 7.8kg in weight and 5 litres in volume compared to the standard battery pack. My short test of the new model on the Fuji Speedway revealed two things.
One, driving a hybrid on a Japanese racing circuit is like eating a cold salad at a barbecue. Two, this new hybrid is nicer to drive than the old one. The step-off to 30km/h or so feels sharper and the throttle response seems more immediate. Even though the acceleration from a standstill to 100km/h is actually slower now (by just over half a second), it’s more linear and easier to apply compared to the “on-off rubber-band” performance of the previous Prius.
The regenerative braking is eff ective and the brake pedal’s action should be natural enough for the driver used to a Corolla or Vios. The steering and handling attributes are still indiff erent rather than incisive, but the suspension (with rear double wishbones) is supple when going straight and stable when cornering. Body movements during hard directional changes are less pronounced than with the old model, but making the new Prius change direction in a hurry is quite silly.
It’s smarter to chill behind the wheel of the hybrid machine, which is happy to oblige with an informative and attractive dashboard (plus an optional head-up display that comes in full colour, a first for a Toyota car), good-quality materials (that include a choice of genuine or synthetic leather) and advanced safety systems (including frontal collision avoidance, lane departure alert and radar cruise control). Appropriately enough, Toyota’s latest eco car is available in lime green (pictured on facing page), said to have been inspired by new green shoots.
