Keen to project a 'green,' eco-friendly public persona, many automotive OEMs are these days talking about their intent to build more hybrid and electric cars. Toyota, however, has always been ahead of the curve – the Japanese company launched the first hybrid Prius almost two decades ago, and despite various challenges and sometimes slow, reluctant consumer acceptance, never stopped improving the car. Indeed, Toyota has sold more than 3.5 million units of the Prius over the last twenty years, so they must be doing something right, right? TKM previewed the 4th generation Prius in New Delhi in November last year and the car is now available in Toyota showrooms in India. Here's our driving impression of the new Prius.
The India-spec Prius is powered by Toyota's Hybrid Synergy Drive (HSD) powerplant, which uses a 1.8 l DOHC 16-valve four-cylinder '2ZR-FXE' petrol engine, with intelligent variable valve timing (VVT-i). This engine produces 95 hp at 5200 rpm and 142 Nm of torque at 3600 rpm. This engine uses Toyota's EGR (exhaust gas recirculation) system to achieve more than 40 % thermal efficiency and, according to the company, offers unprecedented efficiency and greatly reduced NVH levels.
Of course, since this is a high-tech hybrid powerplant, the Prius also has two electric motors working alongside the IC engine. The first motor's primary task is to start up the IC engine and recharge the car's battery pack, while the second motor, which produces 53 kW and 163 Nm of torque, actually powers the car. The motors are fed by the Prius' 201.6V, 6.5 Ah Nickel-Metal Hydride (Ni-MH) battery pack, which gets its charging from one of the electric motors, the IC engine, and the energy recovered by the car's regenerative braking system. It's an amazingly efficient setup, delivering up to 40 km/l in terms of fuel economy (depending on driving style and road/traffic conditions) and admirably low CO2 emissions of 70 g/km.
The hybrid powerplant's combined system output is 121 hp and power is sent to the front wheels via an advanced continuously variable transmission (CVT), which works in perfect symphony with the Prius' HSD powerplant. We'll note here that this CVT feels significantly better than just about any other CVT that we've ever sampled on any car, exhibiting very little of the dreaded 'rubberband effect' and working smoothly and seamlessly in all driving conditions. It's just perfect for the Prius, no question about that.
The Prius, which weighs 1790 kg, can be operated in eco, power and EV mode, and depending on the driving mode selected, the car's onboard computers work their magic with the energy management system, making the IC engine and electric motors work in tandem for delivering either optimum fuel efficiency (in eco mode), or improved acceleration (in power mode), or a balance of both (normal mode).
In EV mode, the Prius is capable of traveling on battery power alone, using just the electric motor, without any assistance from the IC engine. However, unless you're very gentle with the throttle pedal, EV mode is not sustainable. With any major throttle input, the car senses the demand for more power (more than the batteries/electric motor can provide) and automatically switches back to hybrid operation, with the IC engine providing motive power alongside the electric motor. Of course, the switching between the engine and the motors is smooth and completely seamless – it really does work like magic.
DESIGN & INTERIORS
The Prius is not a conventional car, so maybe its design/styling isn't required to conform to conventional norms of what's a good looking car? Perhaps not. Here, at ATR, the car's lines drew mixed responses with the overall consensus being that while the Prius may not be particularly good looking, it certainly looks interesting. It is very clearly and overtly oriental, with lines that evoke well-loved comic book characters from Japanese pop culture. The bodywork is an interesting mix of slashes, creases, curves, scoops and spoilers. If the idea was to break away from conventional design norms and make a definitive style statement, Toyota designers have certainly succeeded in their mission. Also, it's functional design at its best – the Prius boasts a coefficient of drag figure of just 0.24, which makes it very aerodynamic – probably an important factor that contributes to the car's amazing fuel efficiency.
Coming to the interiors, the Prius' cabin feels airy and spacious, with comfortable, adjustable seats at the front, a rear bench that can seat up to three people, fully adjustable steering wheel, colour head-up display (HUD) system, steering wheel-mounted controls for the car's infotainment system and a stubby little gear selector lever mounted on the dashboard. There are buttons that allow the driver to select between normal, eco, power and EV driving modes, while relevant information is displayed on the car's two-tier display.
There's the main infotainment system with a 7-inch colour display, that's easy and intuitive to use, and provides comprehensive vehicle- and journey-related information. The system also has an animated display that shows the hybrid powerplant's operating status, with a graphic representation of power flowing from the engine to the batteries, and from the batteries to the electric motors etc. It's certainly fascinating to watch, especially for tech enthusiasts. Apart from the primary infotainment system display, there's also a smaller colour display on top of the dashboard, which displays information pertaining to the driving mode selected and miscellaneous other vehicle information.
CHASSIS, SUSPENSION & SAFETY
The Prius makes use of Toyota's 'New Global Architecture' (TNGA), which incorporates a high-strength body structure, with body panels made of hot-stamped high-tensile steel, using innovative fastening measures such as advanced adhesives and laser screw welding, which provide the twin benefits of weight reduction and increased structural rigidity. The car rides on 15-inch alloy wheels, shod with 195/65 Bridgestone B250 tyres that offer low levels of rolling resistance.
The MacPherson strut (front) and double wishbone (rear) suspension has a reasonably soft, supple setup that works rather well on our roads. Outright grip, handling and driving dynamics are not the Prius' forte, and aggressive steering, throttle and braking inputs upset the car's balance rather easily. However, as long as the driver bears in mind that this is not a sports car, but a family sedan that's meant to provide safe, efficient transport, the Prius' performance is not bad at all. Acceleration is strong (especially so in 'power' mode), ride comfort is very good, and the whole driving experience is as effortless as it gets – what more can you ask of a hybrid family car that's built around efficiency.
Where the Prius really shines is in the critical area of safety – the car is equipped with a host of safety features, including seven airbags, anti-lock brakes (ABS) with electronic brake force distribution (EBD), vehicle stability control (VSC), traction control, ISOFIX-2 rear seat child restraint system and a tyre pressure monitoring system. With a 5-star safety rating from Euro NCAP and the NHTSA, the Prius' cabin would certainly be a very safe place to be in, in the event of a crash.
On the move, driving the Toyota Prius can sometimes feel like piloting an alien spaceship. Sure, there's still a conventional 1.8 l petrol engine under the hood, but the car's electric motors make a significant difference to the way this car drives. The mild, subdued hum of the electric motors – especially when getting off to a start and when coming to a complete stop – is a gentle reminder of the fact that this is not a garden-variety Corolla. And watching the space-age, sci-fi animated graphics on the main digital display, which show the actual interplay between the car's IC engine, electric motor and battery pack in real time, can be endlessly fascinating.
For now, hybrid technology is expensive – the Prius, imported to India as a CBU, costs Rs 38.96 lakh, ex-showroom Delhi. A new Corolla starts at Rs 15.87 lakh, and offers the same cabin space and ride comfort as the Prius, along with better performance, handling and driving dynamics. (Of course, a Corolla can't match the Prius' fuel efficiency or the sheer technological advancement of its HSD powerplant.) Even the 'mild hybrid' Camry, at Rs 31.98 lakh, is cheaper than the Prius and offers an overall driving experience that's way more luxurious.
There's also another debate to contend with. Are hybrids really as 'green' and eco-friendly as they appear to be at first glance? What is the better option – a smaller conventional IC engine with forced induction (turbocharging and/or supercharging) that delivers a good balance between power, performance and fuel economy, or a bigger IC engine that's primarily used to charge a hybrid's batteries and also provide a bit of extra power to supplement the car's electric motor? The Prius, for example, uses an IC engine that's as big as the unit used on a Corolla, and also has the increased weight, costs and complexity of its advanced electric motors and Ni-MH battery pack. Sure, the Prius is probably more than twice as fuel efficient as a Corolla, but is the trade-off, in terms of price and complexity, really worth it? Answering these questions is beyond the scope of this review – it's an ongoing debate, and the answers will ultimately shape the future of the global automotive industry.
For now, what we can say is that while the Prius is not a very practical proposition in India, it certainly may be a glimpse of the future of personal mobility. Toyota is already moving in the direction of plug-in hybrids, and the Prius Prime (unlike the Prius available in India), instead of only relying on its IC engine for charging its batteries, can also be plugged into an electricity outlet for charging. With plug-in hybrids, there will be even better fuel economy, greater electric-only driving range and, perhaps, a shift to much smaller IC engines. In fact, someday, all Prius cars might be plug-in hybrids. But until that happens, the current model is just about your best bet if you have your heart set on buying a hybrid car and are willing to fork out the big bucks for acquiring a slice of next-generation automotive technology.
TEXT: Sameer Kumar
PHOTO: Bharat Bhushan Upadhyay