British Prius review

Road Tests
Toyota Prius T Spirit Self Park
By Graham Whyte

Using the latest Hybrid Synergy Drive, the clean and green Toyota Prius is perhaps a little too clever.

896 was a busy year: Queen Victoria became the nation’s longest-serving monarch, X-rays were discovered, MDCCCXCVl occurred, and the Toyota Prius was pre-empted by a young electrician from the Black Country.

Whilst Ferdinand Porsche was dabbling with series hybrids, Mr H J Dowsing developed what was arguably the world’s first parallel hybrid, when he fitted an Arnold car with a so-called dynamotor that served both as an electric starter and as a means of propulsion. And when it wasn’t doing that, it charged the battery.

Despite Porsche’s pioneering designs, series hybrids have yet to catch on, whereas parallel hybrids are now quite commonplace – notably the Toyota Prius and various Lexus cars. It is the advent of modern electronics combined with advances in materials technology that have enabled many of these early ideas to be dusted off and put to good use.

Before we go any further, I should perhaps explain the basic difference between series and parallel hybrids. Series hybrids are electric cars powered by traction motors that are fed current from a generator driven by a gasoline engine, which has no mechanical connection to the driven wheels. London’s first-ever motorised fire engine used a Porsche ‘Mixt’ drivetrain working on that very principle.

On the other hand, parallel hybrid cars are powered by a traction motor and gasoline engine working in tandem, both connected to the same drive shaft and one taking over from the other according to road-speed and load. That is the Toyota Prius.

A parallel hybrid takes advantage of the differing characteristics of electric motors and conventional gasoline engines. The former are highly efficient at low speeds and the latter work best at high speeds. Link the two via a common drive shaft and you have the best of both worlds – a high-torque, low-speed traction motor to power the car away from standstill, and a lean-burn gasoline engine to provide efficient tractive effort at cruising speeds. And when the gasoline engine needs a bit more grunt, the traction engine can be switched in to provide torque assist.

And the driver need do nothing: the system is entirely automatic. Moreover, surplus power from the engine is used to ‘top up’ the batteries that provide current for the traction motors, and this is supplemented by so-called regenerative braking in which waste kinetic energy is converted to electrical energy that also charges the batteries.

By way of a bonus, the latest Prius also has a button that enables the driver to engage electric traction only. The range is limited – about 1.25 miles – but nonetheless during that period, the Toyota is silent, emission-free, and no greater threat to the planet than a cucumber.

The obvious benefits of what Toyota calls Hybrid Synergy Drive are low fuel consumption and low emissions – but neither at the expense of performance. Despite returning 65.7 mpg on the combined cycle, and achieving tailpipe emissions of 99 g/km on the extra-urban cycle, the 1.5-litre Prius will still pass 62 from standstill in a respectable 10.9 seconds, en-route to a maximum speed of 106 mph.

Ken obviously approves: the Prius is exempt from the London Congestion Charge, which represents a saving of up to £2,000 a year. In the right quarters, this makes the range-topping T Spirit Self Park (as tested) something of a bargain at £20,677. By way of a bonus, all Prius models, thanks to a combined-cycle CO2 rating of 104 g/km, fall into Band B for Vehicle Excise Duty (VED).

Did I say Self Park? Absolutely. Not content with Hybrid Synergy Drive, Toyota has designed a car that, quite literally, will park itself. Whether you want to parallel park (in a row of cars parked at the kerbside), or series park (as in a supermarket car park) you can take your hands off the steering wheel and let the Prius do it for you.

The fact that you might need such a driving aid is a separate issue, but if parking is your Achilles heel, look no further.

It takes some practice to set up the car for either reversing manoeuvre, but once you get the hang of correctly positioning the car, it will park itself with some degree of accuracy. Using parallel parking as an example, it works as follows.

You’ve seen the space you want in a line of cars. Stop about two to three feet away from the car ahead of the gap, with your back door roughly opposite the target car’s B-pillar. Engage reverse, using the stubby, dashboard-mounted selector lever. That will switch on the reversing camera. A box will then be superimposed on the screen to show where the car will finish up. Provided the box is green you can proceed with the next stage. (If the box is red, its position can be toggled until it turns green although that doesn’t always work.)

So far, so good. You will then be asked to straighten the steering wheel (if necessary), remove your hands from it, cover the footbrake, and press the accept command. That done, the car will immediately start to inch backwards, with the steering wheel turning to the left, then to the right, of its own accord. Should the reversing speed become too high you will be asked to apply the brakes. The whole manoeuvre is monitored by the camera and associated proximity sensors. Once complete, a voice will tell you job done, and all that remains is for you to centre the car in the gap. Meanwhile a three-mile queue of traffic has built up.

I tried it about a dozen times, with increasingly better results, but not once was the final position quite as accurate as I could have managed on mirrors alone. I have no doubt that most experienced drivers would reach the same conclusion.

As toys go, it is a bit of harmless fun that is best practised away from the High Street. As a serious driving aid, it should be condemned, as it provides yet another example of enabling drivers to abdicate their responsibility.

In every other respect, I am sure Prius drivers are extremely responsible, and certainly take seriously their environmental footprint. Toyota hopes to woo such drivers away from what it calls ‘premium diesels’ (aka Audis) and as such promotes the Prius as conveying a similar status.

Unfortunately it doesn’t work. Whilst the Prius is certainly well-equipped (more of which later) its appearance lacks adequate gravitas, and from certain angles its large body and small wheels make it look as if might be made in India. The interior, too, whilst undeniably comfortable, fails to ignite any passion, and therefore the car’s emotional dividend must be derived from its discreet footprint rather than from a sense of prestige.

Having said that, the equipment list is quite comprehensive, and the T Spirit specification includes climate-control air-conditioning, vehicle stability control, cruise control, GPS with traffic-avoidance, a JBL premium audio system with a 6-CD autochanger, and, of course, the self-park facility. A lot of car for the money, then, but lacking any real charisma.

In keeping with its anodyne character, the Prius is easy to drive rather than exciting or sensational. Apart from neutral, the little gear lever offers three main options: forward, reverse or park, in which position, the foot-operated parking brake is supplemented by an electronic brake applied by pressing a button on the fascia. Transmission is constantly variable (CVT) and there are no gears as such, nor any virtual gears selectable ‘Tiptronically’. So it’s squeeze and go, with no appreciable gear changes. Once the engine is warm, the car invariably pulls away on the traction motor – and therefore is silent – and as road speed builds up, the gasoline engine seamlessly takes over. The ‘gear lever’ offers a fourth position – B or Brake – which enhances the regenerative braking but at a steady throttle creates the sensation of driving into a robust and variable headwind.

As you might imagine, the Prius carries around a substantial bank of batteries, which occupy part of what would otherwise be a sizeable boot. Sensibly, Toyota has not scavenged cabin space to accommodate the batteries, and consequently any compromise is confined to the load space. The rear legroom is extremely generous whereas the boot volume is a modest – for a D-segment hatchback – 14 cubic feet, although this can be augmented by folding the asymmetrically split rear seats.

Unlike those fitted to some early hybrids and EVs (Electric Vehicles), the batteries fitted to the Prius are intended to last the lifetime of the vehicle, and in any case are covered by a 5-year guarantee. And when the vehicle is eventually due for scrapping, Toyota will take it off your hands and deal with all the messy business of battery disposal. Service intervals, too, are no different from an ‘ordinary’ car, and so running a Prius requires no special considerations, other than to register it with TfL in order to get Ken’s benediction and your free pass.

Driving the Prius is no more fun than looking at it. OK, so you can select EV mode and creep up on cyclists, but I am told that is not the point of it. But the real point actually becomes lost, quite quickly. Because the Prius hybrid system is so subliminal, it is easy to forget that you are driving something rather special. It’s nice when the engine switches off every time you stop – silence is golden in this day and age – but otherwise the ingenuity of its Faraday-meets-fossil-fuel mechanism is rapidly absorbed by the rigours of everyday driving.

And the rigours are not new either. Mr Dowsing’s Arnold was built by Walter Arnold of East Peckham in Kent, who was probably the first man in Britain to collect a speeding ticket. Magistrates in Dartford fined him one guinea (£1.05) for exceeding what was then the speed limit for horseless carriages – two miles an hour. The arresting officer, Constable Ernest Gatso, told the magistrate: “The defendant’s car ‘ad two engines, M’Lud. If ‘e thinks ‘e can get away with it, ‘e’s got another think coming.” Shame another think took a hundred years or more.