It may be different for the enthusiast but say the word hybrid to the layman and he’ll automatically associate it with the Toyota Prius. And now, the third generation is here, and slated to be launched in Malaysia next month. Let’s have a look at the new iconic hybrid Toyota that you’ll be able to buy at showrooms before the end of the year.
First of all I think it’s best to define what a hybrid car is, and the various types of hybrid cars available on the market. A hybrid vehicle essentially combines two or more power sources to move the vehicle. It commonly refers to hybrid electric vehicles, which combine a combustion engine with electric motors.
When you implement a hybrid system, there are a few ways to configure the combustion engine and electric motors. With the introduction of the Honda Civic Hybrid, we’ve been introduced to the concept of a mild power assist hybrid system, or a mild parallel hybrid system.
In a mild parallel hybrid system, the internal combustion engine is always used as the primary power. A electric motor is installed between the engine and the transmission. It is only used to assist the combustion engine whenever needed, hence Honda calling it an Integrated Motor Assist system. Because the motor steps in whenever the driver demands more power, a smaller and more fuel efficient combustion engine can be used. However with this configuration there is no such thing as a zero emissions full EV mode – the car cannot run solely on the electric motor.
And then you have series hybrid cars, where a combustion engine running at a constant most efficient RPM is used as an electricity generated to power an electric motor, which drives the wheels.
The THS Hybrid Synergy Drive system in the Toyota Prius is of the variant called a full hybrid, a power-split hybrid or a series-parallel hybrid. It offers the best of both world, can run on either the combustion engine only, electric motor only, or both, but is heavier as it has more parts, and more complicated in design.
THS consists of an internal combustion engine, two water-cooled motor-generators (electric motor with dynamo functions), a powersplit device, and a battery pack. The first motor-generator functions as a power generator, converting the internal combustion engine’s mechanical power to electric power, which recharges the battery and supplies electricity to power the second motor-generator. The second motor-generator is used to drive the vehicle. It is mounted on the driveshaft. It also serves as a dynamo during brake-energy regeneration.
Power from the internal combustion engine is split via the power split device and goes to either the front wheels or the first motor-generator. The Prius combustion engine revs independently of the vehicle speed much like how a car with a CVT transmission would, but there is no CVT transmission in a Prius! Some trickery between the power split device, motor-generators and the combustion engine play around with the engine revs that one would find confusing, but the bottom line is the end result is perceived to us as CVT-like. Toyota calls it an ECVT system.
But the best part of such a system is the EV mode where the car runs on the electric motor only. On one end really fast 0 to 100km/h acceleration times can put a smile on your face but I found out that the other end is also true! Complete silence from the car while you are creeping through a traffic jam or looking for parking in a parking lot can be strangely satisfying, it could be something to do with the fact that your car can do something that most likely no other car in that parking lot can do.
The internal combustion engine of the new Prius is the 2ZR-FXE, an Atkinson cycle engine with 1.8 litres of displacement. This is up by 0.3 litres from the previous 2nd gen Prius 1.5 litre engine. The new engine puts out 99 PS compared to 77 PS from the 1.5 litre engine, and 143Nm of torque at 4,000rpm. Now why does a 1.8 litre engine put out so little power you ask? It’s because of the Atkinson cycle – it’s more fuel efficient however has less power density. The engine is now beltless thanks to an electric water pump. The combined output of the motor-generators produce 60kW and 207Nm of torque.
The Prius continues to use a NiMH battery. Some competitors have talked about starting using lithium ion and Toyota says they also have a li-ion battery coming by the end of this year but according to Prius chief engineer Akihiko Otsuka, NiMH and Lithium Ion both have pros and cons. EVs might need the larger capacity of lithium ion batteries, and they can be larger because of the lack of a combustion engine and fuel tank, but in hybrids where the battery can be smaller and of less capacity, NiMH is more suitable as it can sustain a high power output over a shorter period of time. But for plug-in hybrids in the future, they can benefit from lithium ion technology.
Something interesting is an optional feature which is a solar panel on the roof. This panel doesn’t recharge the battery but it actually helps keep the car cool while it is parked under the sun. Unfortunately from what I hear, UMW Toyota specifications for the Prius in Malaysia will not carry this solar panel.
There were no city drives as part of the test drive session that I attended at the Tokachi International racetrack in Hokkaido. Instead, Toyota had designed a series of acceleration and braking patterns set by a pace car over a total of 10.2km on the racetrack that’s meant to emulate city driving. While this isn’t really an indicator of real life driving, CBT’s Thomas Huong and I managed to score a nice average 31.6km per litres fuel consumption, which was the most economical figures of the day.
We later repeated the same track run at full throttle and managed to score about 9km per litre, which is still pretty decent considering it was pedal to the metal for most of the track. I think the Prius would be able to score a decent 20km+ per litre in real life fuel consumption, which is impressive for largeish (you could call it European D segment) car with a 2,700mm wheelbase. The chassis is a common one called the MC platform shared with some Toyota cars such as the RAV4, Estima, Avensis and Auris.
The model with the 17 inch wheels was actually pretty surprisingly fun to drive on the track thanks to a decent chassis with a compliant suspension coupled with the strong torque of the electric motor assist. Grip levels and the tight handling were far lower on the second gen Prius and third gen models with smaller wheels, with VSA stability control kicking in to reel the car in way too often. Big difference – just shows you how much wheels play a part in the dynamics of a car. But all in all, really very surprising for a car that’s focused on boring old fuel economy. Could be something to do with the fact that the chief engineer drives an Alfa Romeo…
The first thing you notice about the interior of the new third generation Prius is the fact that the big Electro Multi Vision touch screen is now gone. Other Prius trademarks are still there such as the tiny shift by wire gearknob and the On button that does nothing but bring some of the dashboard lights up to life. It doesn’t feel like you’re turning a car on but more like an electrical appliance.
The EMV system has been replaced by integrating more displays into the instrumentation panel located at the forward-most end of the dashboard, closest to the windscreen. Stuff like the fuel consumption bar graph history and the real-time display monitoring what sources of power the car is currently powered by are much smaller now but functionality-wise it is much better as they can all be looked at by glancing quickly at the panel instead of looking left at the EMV as per the 2nd generation Prius.
This is all in the interest of keeping the driver focused on the road. Another feature that helps in this aspect is the Touch Tracer system. As the vehicle monitoring display is now near the windscreen, there is no longer any touch screen functions. Instead you control the various displays via steering wheel controls.
You may feel like taking your eyes off the road and glancing at what your steering wheel to look at what button your fingers are resting on. With Touch Tracer you don’t have to do that. The steering wheel controls have dual level sensitivity. Touch lightly and a display on the instrumentation panel that mimics the steering wheel control design shows you what button your finger is touching. Then you activate the button only if you press down a little harder.
All in all the changes to the new Prius makes it look and feel more like a normal car but with exceptional fuel economy rather than a hybrid. The exterior looks way better, less space-age and more sporty, but the interior is more like a regular car, and somehow while it looks much more modern it feels much less expensive compared to the 2nd gen Prius. It’s not just the dashboard but the instrumentation panel – the graphics look quite pixelated. But the third gen is definitely an improvement over the 2nd gen, and the Hybrid Synergy Drive system trumps the motor assist systems of its competitors both in owner experience and in terms of fuel economy.
However in Malaysia the estimated price is expected to hover around a Camry 2.4′s price. That’s quite a premium and if you’re buying this to save fuel, that’s alot of fuel “prepaid”! The drawing factor will undoubtedly be the whole hybrid lifestyle such as the ability for the EV mode, and making an eco statement.
And we still don’t have any clear answers as to how long the battery lasts and how much it costs to replace, though Toyota claims it will last over 10 years and possibly the lifetime of the car. There needs to be a solid answer and guarantee for this. Perhaps a longer warranty for the battery compared to the rest of the car will give better customer confidence. More details on the Malaysian specifications for the Prius will come when the car is launched next month.
GALLERY: Toyota Prius Product Shots