Toyota Prius Hybrid: Detailed Review

Toyota pioneered the concept of hybrid vehicles nearly two-decades ago with the Prius. Toyota rightfully so, take credit for making hybrid cars, where the internal combustion engine is supplemented by an electric motor, popular across the world. While Toyota now has a plug-in hybrid Prius in their global lineup, the Prius in India won’t need you to plug it in, you just need to supply it with petrol to keep it going. Toyota launched the fourth-generation Prius globally in late-2015 and it has finally made its way to India. Since the Prius is imported to India as a completely built unit (CBU), the latest generation of the popular hybrid costs double of what Toyota charges in international markets. So, it’ll be safe to say that the new Prius is going to be a rare sight on Indian roads.

But the crucial question for this environmentally-conscious car is just how much more green is it in the fourth-generation? And is the Prius now a better everyday machine, or is it just a bold statement?

Exterior

The design of the new Prius is loud. Yes, it may be polarising and some may even call it futuristic and sporty, but it is certainly not a design that one can get used to easily. The Prius may not be as big as the price tag suggests. It is in fact a tad bit smaller than the more affordable Corolla Altis. Speaking of dimensions, the Prius is 61mm longer, 15mm wider and 20mm lower than its predecessor. The sharp angles and lower stance make it more aerodynamic and help it lower the centre of gravity too.

The loud exterior design makes the Prius stand out. The most noticeable design element up front has to be the headlamps. They have multiple edges and look sleek and sharp. The the ‘V’ shaped bonnet and the front bumper are heavily sculpted and make the Prius look more like a performance car rather than an environmentally-friendly hybrid. Also worth pointing out is that the top edge of the nose now sits 70mm lower to aid aerodynamics. This helps the Prius cut through the air better, resulting in a drag coefficient of 0.24cd, which is even better than the Nissan GT-R!

What’s interesting here is the way the drooping roofline meets the sharply rising shoulder line. Once you absorb all the cuts and slashes at the front and the sides, the rear feels like it sits a bit low, but the design is an evolution of the third-gen Prius. There's the signature glass treatment on the boot which makes the upper metal portion appear like a virtual spoiler. The vertically-stacked LED tail lamps aid the futuristic appeal of the Prius. Overall, Toyota seems to have taken a slightly different approach with the new Prius. The design is bolder than before and tries hard to stand out in a crowd. So, is that good or bad? That will depend on your tastes.

Interior

When you step inside the Prius, it is quite evident that the cabin can accommodate four average-sized adults in reasonable comfort. However, when compared to the older version, you do sit a lot lower. The TNGA platform has been built to keep the centre of gravity as low as possible. As a result, the front and rear seats have been lowered. In fact, it is the same reason why the battery pack now sits below the rear bench instead of the boot floor. So, despite the sharply sloping roofline, headroom is not a big concern until you're over six-feet tall.

The interior design of the new Prius is more concept-car like. There's a large floating console on the dashboard that houses the infotainment system, air-con vents and the drive-selector lever. There's a heavy dose of white and black plastic with soft-touch materials as well. You won't complain of the material quality but the glossy white panels are a bit too much for my liking.

The Prius gets a touchscreen infotainment system equipped with a 10-speaker JBL system. The touchscreen takes inputs seamlessly and the audio quality is reasonably good. On days when you want to give your audio system rest, you won't complain about outside noise seeping into the cabin. The Prius' cabin lowers rush-hour decibels (read honking) well but the Bridgestone B250s ruin the in-cabin experience even before you hit speeds of 70-80kmph. So much so that I'd suggest anyone going for the Prius to get a good set of silent rubber.

Ergonomics, as expected from a Toyota, are well-sorted with all controls easily falling at hand. The steering wheel offers tilt- and telescopic-adjustment and those who like to sit snug in their cars will appreciate the driver’s seat with the steering set to its lowest position. The view out from the front and side windows is excellent. However, what’s impressive is the addition of the glass panel on the boot that makes parking the Prius an ease. Nevertheless, you do get the parking sensors and camera to sneak in and out of tight spots easily.

Rear view from the IRVM. Notice the glasswork.

The front seat lacks under-thigh support (and gets manual adjustment!). Since I'm about five-feet-nine, I believe a lot of us will face this issue.

The rear bench is, however, more comfortable for someone of my height. Rear passengers don't get separate air vents, but the air-con system on the Prius works well. In the blazing Delhi heat the air-con cooled the cabin fairly quickly too.

The instrument cluster on top of the dashboard also needs a special mention. I'm not a fan of centrally-mounted display units as they divert your attention in comparison to the traditional ones that sit behind the steering wheel. However, considering the detailed information that the Prius' unit gives out, it's best placed in the middle. Importantly, it's well-lit and covered which makes it readable even under harsh sunlight.

Three different screenshots of the informative centrally-placed instrument cluster

Overall, if you put the Prius' price in picture, it just doesn't pamper you the way its price competitors do. Even if some fine day the government goes lenient on hybrids and remove the import duties altogether, the Prius will still not be able to wow you in comparison to the Octavias and Corollas. Being futuristic, minimalistic and efficient is a trait that the Prius can never part with. As a result, Toyota sheds everything that goes against this core philosophy.

Engine & Drivetrain

The Hybrid Synergy Drive that powers the Prius is a combination of a 1.8-litre petrol engine that produces 98PS and a permanent magnet synchronous motor that draws power from a 6.5Ah nickel-metal hydride battery and puts out 72PS in parallel configuration. The total output of the package is rated at 122PS.

The Prius' AI (artificial intelligence) selects the power source by itself and juggles between the motor and engine instantaneously depending upon the power demand. The shift in power source is seamless and the occupants remain unaware of what's happening under the hood at all times

The Prius gets multiple drive modes – Eco, Power, Normal and EV. In EV mode, only the electric motor powers the wheels until the battery runs out of juice. If more power is required or the battery runs out of charge, then the engine takes over. Eco mode is the one in which the Prius appears the most sluggish. It feels better in Normal mode but it's the Power mode in which it is at its peppiest best. But no matter what's powering the wheels, every time you floor the throttle there’s a little bit of lag before the power required hits the road.

In Eco mode, the Prius is slightly reluctant to accelerate when you press the gas pedal. Switch to Normal mode, and the acceleration is fairly quick. Now, you might expect it to be quick in Power mode where throttle inputs are sharpened for better power delivery. Unfortunately, it still isn’t quick enough to push you into the seat.

Incidentally, the 1.8-litre engine is the same block that is used in the Corolla Altis petrol. However, the way the engine works has been revised to deliver higher efficiency.  While driving around I couldn’t help but wish there was a tachometer in the Prius as  it could have given us a better perspective of what the engine is doing.  The Prius is eager to respond to throttle inputs, which could be down to the torque produced by the engine and the electric motor. The 1.8-litre, 4-cylinder petrol engine produces a peak torque of 142Nm at 3600rpm while the torque output from the motor is a constant 163Nm. Nonetheless the peak combined output of the hybrid drivetrain is 122PS, which lower than what you’d expect. This is a result of where and when the two drive sources work optimally. It's difficult to make out how much torque you're getting at any particular instance while driving, nevertheless the Prius does have a spring in its stride.

Overall, the driving the Prius is like driving any normal petrol car. But when you move from standstill the silence feels a bit eery while the electric motor propels you forward. And you only get the feeling that you’re saving fuel when the car’s idling, but that lasts only till you have enough charge left in the battery. As you spend more time with the Prius it isn’t as silent as you would have thought. In a bid to give the drivers a greater sense of connection with the machine the 1.8-litre petrol engine emits  a sporty burble. This note becomes apparent when you push past 50kmph.  Given the power-split function function the engine often sits at higher revs to power the wheels and generate additional electric charge. At these times the engine noise becomes quite annoying. Even while commuting for extended periods you realise that the cabin isn’t as silent as you’d expect. Apart from the engine, a bit of road noise also creeps into the cabin.

For geeks – We mentioned in the beginning that the engine and motor in the Prius are in a parallel setting with each other. A parallel configuration means both the power sources (engine and electric motor) can drive the front wheels simultaneously and separately as well. In the Prius’ case, the power is transferred to the wheels via an E-CVT transmission, which is different and complex to decode in comparison to the CVT transmissions that regular petrol-powered cars get. The reasons are:

1. It has to transmit power from multiple sources, petrol engine and electric motor in the Prius' case.

2. Transfer power to the wheels from a very high revving motor

So, how is the fourth-generation better than its predecessor?

More electric kilometres – Toyota has always ensured that with every generation, the Prius becomes more fuel-efficient than before. In our fuel efficiency tests, the new Prius managed to deliver 19.5kmpl within city limits and 31.2kmpl on the highway, which is impressive considering the motor alone can power the front wheels for just 4kms. In comparison, the older version could do so for only 2kms. The primary reason lies in the batteries, which now have a capacity of 1.31kWh, which is almost double than before.

More efficient engine, motor and transaxle – The Prius retains its 1.8-litre petrol engine that generates 98PS of maximum power at 5200rpm. The peak torque of 142Nm is achieved at 3600rpm. The engine has been re-engineered resulting in better thermal efficiency than before. Some more measures have been taken to improve the engine's fuel efficiency. The motor and the transmission are also lighter than before.

Denser batteries – While the Prius is available with Li-ion batteries as well, India still gets Nickel Metal Hydride batteries. NiMH batteries are cost-effective, but they have a high self-discharge percentage compared to Li-ion batteries. Hence, it can be said that these batteries are less efficient than Li-ion batteries. However, the batteries have been made dense so that they can be packed in a smaller place. As a result, the battery pack is now situated under the rear bench which frees up the boot and also improves the front:rear weight balance.

Ride, Handling & Braking

There is a firmness in the Prius’ suspension setup which is likeable. It's only at speeds below 40kmph that you feel the ride is a bit on the harsher side as some of the road irregularities filter into the cabin. As speeds increase, so does the ride quality. The new Prius also gets a double wishbone suspension setup at the rear which is a big improvement over the torsion beam setup used previously. In the Prius’ case, this setup is used to strike a better balance between comfort and dynamics. One big positive is that it doesn't roll or pitch much when changing lanes or under heavy braking.

At highway speeds, a lower centre of gravity keeps the Prius stable. However, you can't call the Prius a driver's car. Change lanes quickly, or turn in over 50kmph, and you'll find  that the rear wheels take time to follow the path that the front wheels traverse. The economy-friendly tyres also end up squealing a lot more than you'd like.

While the steering is feather-light at parking speeds, it does weighs up as speeds rise, but it doesn't communicate everything the wheels tell it. Brakes are sharp, and there's bite at the very press of the brake pedal. A 'tch-tch' sound reminds you that there's regenerative braking somewhere charging the batteries, but it's not enough to slow down the 1790kg Prius by itself. So the disc brakes at the front and the rear shed most of the speed. Our test data shows that the Prius slows down from 100kmph to zero in 3.46s and 44.6m, which are respectable numbers.

Verdict

Hybrid cars are not as common in India as in some other parts of the world. The Prius is a global icon in the green car space and it is unfortunate that its sticker price of Rs 38.9 lakh (ex-showroom Delhi as of May 17, 2017) is so high in India. Blame that on our import duty structure. As a result, the Prius still remains a halo product for Toyota India and not a mainstream car. However, even if it doesn't sell well in India, the new Prius’ extroverted  design, concept-car like interiors and hybrid status will help create a more cool and appealing image for hybrids.

So, with a more practical and affordable hybrid option in the Camry, the Prius won’t be the sensible pick. But, the Prius is here to flaunt Toyota’s green credentials proudly. So, if you want to do the same, the Prius is peerless, and while it won’t pamper you it now does a much better job of tackling Indian roads and traffic than before.

Words: Jagdev Kalsi

Inputs: Kartikeya Singhee & Nikil Jonathan