| First Drive | Stockholm, Sweden | Toyota Prius |

This is the third Prius. It's the one that Toyota hopes will complete the gestation of its environmental archetype, finally taking it from being a flawed link to our automotive apogee - genuinely planet-harmless personal transport, that is - to, well, a not so flawed one. Toyota never thought it was flawed, of course. But it was, wasn't it? The first one, released in 1999, was just plain weird, and the current version, despite its success, was caught up with and eventually surpassed by - of all things - diesel cars; surpassed in the environmental tests that matter, that is - those linked to taxation.

This Prius aims to put clear water between it and its oil burning peers and stay at the top of the low-emissions pack until electric cars come along, when emissions will be actually just clear water.

In the Metal

The Prius retains the familiar rump-heavy silhouette of its predecessor - a shape now adopted by the Honda Insight - but sharpens the details up conspicuously. There's a chiselled, nose forward look to it; in fact it's... good looking. Even the most ardent Prius proponent couldn't say that about the outgoing model. This iteration looks like Trinny and Susannah got hold of the last one: same old body, accessorised to the hilt, and now all of a sudden disconcertingly alluring.

Toyota is inexplicably inconsistent when it comes to its interiors - and we include the Lexus brand in that - but it's got the Prius right. Despite being fashioned from hollow, grainy plastic surfaces, the cabin architecture strikes that difficult balance between interesting design and intuitive layout. Like the exterior, it's the details that elevate it: the central air vents (which to us look thin enough to challenge the Lexus RX 450h for the dubious honour of 'world's thinnest') align nicely with the adjacent panel that runs between the dash top and the twin level glove box (another nice touch, because, for a change, both levels are actually useful).

Our test car was a fully loaded 'T-Spirit' model, though for once that might have been the most appropriate one because Toyota reckons it will account for half of all sales. Still, even without top-level accoutrements like satnav and leather, the cabin is designed with enough flair not to sink into Latvian supermini territory if you don't have those things. The fundamentals that make the Prius properly impressive - like the massive dual-level central storage bin and the high 'floating' centre console complete with blue transmission stick top - will, of course, still be there. It's spacious too, with a decent amount of rear legroom remaining even with a six-footer in front. More driving position adjustment would be nice though.

What you get for your Money

The Prius is expensive - a fact made yet more apparent as Honda's Insight undercuts it by over £3k - but the Toyota is also well-equipped and gratifyingly cheap to run. And, vitally, it makes the Insight look last-generation. It's £18,370 for a T3 model, rising through T4 and up to T-Spirit at £21,210. The thing is, it feels every bit the technological flag bearer it purports to be, even from a spec point of view, and even at base level.

All cars get a head up display, 'touch tracer' switches for the wheel that activate a sort of three-dimensional 'floating' display element in the central instrument cluster, automatic air conditioning, seven airbags, a push button starter, fog lamps and 15-inch alloy wheels - though they're weird because they've got plastic wheel trims attached to the spokes, which Toyota bafflingly claims are there because the wheels are so light, which makes no sense. But hey, they're probably the world's first hybrid wheels, so there you go.

T4 adds Bluetooth, cruise control, automatic wipers and a better stereo, and then T-Spirit gives you satnav, parking sensors with a reversing camera, and an HDD stereo. The solar panel you see on our pictures, which can power the air conditioning so owners can switch it on remotely to pre-cool the interior, is an option for T-Spirit cars too.

And, of course, you get Hybrid Synergy Drive - the only full hybrid drivetrain on the mass market (unless you count the Lexus RX as mass market), and one which - and this is the double-edged sword with which Toyota aims to slay every diesel-powered environmental special there is - achieves 72.4mpg combined and a tax evading 89g/km.

Driving it

Toyota has comprehensively overhauled its full hybrid drivetrain to make it better in every way. And it's really obvious when you drive the thing. There's a level of composure - a calmness and a smoothness - that you perhaps don't expect from a car with so much going on under the skin. The highest praise you can give it is that you never have to make any excuses for it; it doesn't feel heavy or sluggish and nor is the interior space heavily compromised by its beneath-the-surface trickery. It's no driver's car (nobody will ever claim it should be) yet it also doesn't have any one obvious flaw.

Let's assume you completely disregard its environmental remit and drive it 'normally', with no heed paid to consumptive parsimony. You'll find the powertrain picks up pace enthusiastically enough to negate the need to thrash it - but even if you do it remains strong and relatively quiet. The transmission is of the constantly variable type, so it's prone to whine under heavy acceleration - but as mewling CVTs go, it's relatively muted - quiet, even. There's a faint and constant shudder transmitted from the wheels, but the ride is otherwise settled - soft enough to flow over most surface imperfections, but with an edge of firmness enough to keep the car flat and controlled. It neither lolls about nor thumps over bigger pocks on the ground.

And it's actually half-decent when you start turning the wheel. Where you might expect a lethargic steering rack, instead is a fairly tractable one with little slack and a bit of weight. It's no Focus RS, but nor is it anywhere near as compromised a driving proposition - be that on the motorway, through town or on a sweeping back road - as it could easily have been. In short, then, it drives like a good hatch.

Worth Noting

Hybrid Synergy Drive. That's worth another mention, surely? Unlike the Insight's hybrid system, which uses an electric motor in tandem with the engine for power gains and fuel savings, the Prius's 1.8-litre VVT-i petrol unit (up from 1.5-litres) can operate independently or in tandem with the electric motor, combining to give a total output of 134bhp - up from 112bhp - and it's cleaner too, remember.

It has three modes: EV, eco and power. EV mode is standard, which means the car will try its best to operate on electricity alone, but will kick-start the petrol engine if you put your foot down too hard. You can press a button marked 'EV' that puts it into pure electric mode, but you must stay below 31mph and can only travel just over a mile before the battery runs out. Eco mode recalibrates the throttle to smooth out your leaden-footed inputs and controls the air conditioning to make it less active and conversely, power mode sharpens up the throttle and boosts the power for better acceleration.

And this is all linked to an easy-to-follow bar graph in the centre instrument binnacle that shows you whether you're driving like either an environmental activist or a normal person, and it shows you how much charge there is in the battery, as well as when it's recharging using energy recovery from either engine braking or use of the brakes - brakes that are a little hard to regulate, actually, like there's a magnet clamping the callipers to the discs.

Summary

Ultimately, the new Toyota Prius succeeds because its technological brilliance never gets in the way of it being a really easy car to justify; it's spacious, cheap to run, attractive and decent to drive. Some will find the list price prohibitive, which is fair enough, but this time around, meeting the big outlay can be justified by plenty more than just making a statement.