Fiat 500 TwinAir

Fiat 500 TwinAir

Not so much
>> It's still expensive technology
>> You can only get it in a 500
>> Twin-clutch gearbox isn't here yet

The very first Fiat 500 turned up with a wobbly little two-cylinder engine and half a century later, Fiat's cult car has reverted to type. But where the original went with two pots for cost reasons, the modern interpretation has taken the same route for better fuel economy, lower emissions and weight saving. And the little jigger actually works.

Just 900cc of two-cylinder engine now occupies the seemingly gaping hole where the 500's 1.4-litre four-cylinder engine used to be. It shares the space with a compact five-speed manual gearbox and not very much else.

When you stop laughing, you can start reading again, because this car will come to Australia. And it will spread out into other Fiats; most likely the Ritmo first.

And it's not the asthmatic little number you might imagine. The TwinAir (Fiat name for the new engine) uses a combination of turbocharging and the innovative MultiAir valve-control system to bang out 85 horsepower (62kW) and a more-than-useful 145Nm of torque – the latter at just 1900rpm.

In something the size of the 500, it's not only quicker than the old base four-cylinder, but it's 30 per cent more economical. That it is 10 per cent (13kg) lighter and 23 per cent shorter as well means it can be shoehorned into strange little spaces. And, when Fiat launches in its dual-clutch gearbox late next year, Fiat will fill the big hole under the bonnet with an electric motor on one axle to cheaply turn the 500 TwinAir into a hybrid.

There are plenty of cars out there slower to 100km/h than the 500 TwinAir's 11 seconds but very few of them boast a combined fuel economy figure of 4.1L/100km. And when we tested it, we found we could get pretty close to that without really trying.

Tellingly, its urban consumption figure (which is traditionally much higher) is only 4.9L/100km, while its extra-urban (highway) figure is 3.7. And it only emits 95 grams of CO2 per km as well.

Fiat hasn't just cut two cylinders off any old engine, either (thankfully, because the basic layout of most of its four cylinder engines dates back to the mid 1980s). A team of 200 engineers worked for two years – which is phenomenally quick in the car world – to make an engine that was all-new from the ground up, and based entirely around getting the best economy and performance out of its MultiAir valve-control system.

There's an all-new combustion chamber design, to get the most bang for each buck you spend on petrol. There's a special chamber to house the balance shaft (two cylinders without a balance shaft would be inherently, umm, really wobbly) and it's all the basis of not just two upcoming TwinAir engines, but soon to be released three and four-cylinder Fiats as well.

There's no direct fuel injection to be found anywhere, though, because with MultiAir's more accurate, flexible valve control, direct injection's benefits are greatly reduced. It then falls victim to a cost-benefit analysis.

But sitting in the 500 TwinAir with the engine fired up, you forget all about its technology and its eco-friendly tricks and you just revel in its completely original soundtrack – but you have to open the windows to do it properly, because it's all silence and smoothness with the windows up.

This engine could easily have tripped over into a mess of vibrations and unwanted noise, but it hasn't. Instead, even at idle, it's all charm. It's also all new to your ears, too, and they have to become accustomed to a whole new range of sounds at different revs.

At 2000rpm, it sounds like it's doing 1000. At 4000, it sounds like 3000 and at the 6000rpm redline, it sounds like it's doing about 4000. That's because there are a lot less 'bangs' going on inside the engine than you're used to hearing – exactly half as many, actually. That also makes it sound a lot less stressed than you think it should be for the revs it's doing, and early on it feels just like a four pot.

It moves off pretty comfortably, with a broad, funny little warble rumbling with a much deeper note than you could believe. Forget ring-a-ding three-cylinder engines you might have heard, because it's nothing like them.

Indeed, it struts its own stuff in its own way. It's strong enough, too, especially around town. There's never a query about keeping up with the traffic and it's got a real, sparkling little crackle and howl to it from 3000rpm to around 5000, especially in the taller gears.

Its real strength is flexibility. At 1900rpm it has more torque than the old naturally-aspirated four-cylinder 1.4-litre and it's really strong even from idle. It's not quite stall-proof, but with its soft clutch pedal, it's not miles away from it.

The start-stop system Fiat uses isn't as sophisticated as some, but it's got a big impact on the economy. Unlike, say, Audi's system, the 500's just switches off at the lights and that's that. Audi's (more-expensive) system keeps the air conditioner running while it can, then re-fires the engine to prevent the cabin getting too hot. No such extra thinking here.

Where other engines have a Sport mode to pump up some extra boost out of their turbochargers or their engine software, the TwinAir has an Eco button that reduces the torque to 100Nm, gives it slower throttle response and reduces the steering assistance to give it maximum fuel economy. It's not exactly spritely this way, but you can live with it in heavy traffic.

It's got it all, really, but the big shame is that it's in the 500 first. Fiat will argue that it's the spiritual home of the two-cylinder engine and it would be right, but it's not the best chassis in the Fiat range for exploiting, well, most things. It's based on the humble, unpretentious Panda and, basically, has just enough suspension to keep its underbody off the ground.

You sit too high in the driver's seat (even higher in the non-adjustable passenger's seat) which leaves you a bit too removed from everything that's happening below decks. And the 500 has a lot going on below decks, because it gets terribly busy over bumps, especially if you find them mid-corner.

Then there's its pedal positioning, which makes it impossible to neatly heel-and-toe, so you end up with jerkier downshifts than you need to have. That's going to change when it gets the dual-clutch transmission next year, but until then, you miss a lot of gears initially, because you often don't aurally comprehend what cog you should be looking for – the sound is really that different.

It's smooth, though, and the 'wobulator' inside the engine does a masterful job at cancelling its vibrations. There's a lot of movement in the engine on its mounts when you look at it inside the engine bay, but from inside the cabin it's all smooth sailing.

There are few real rivals for it, to be honest. There's the smart fortwo, which runs it close on fuel consumption, but is expensive for what it offers and has only two seats and virtually no luggage space. We reckon the 500 TwinAir leaves it for dead. In fact, we'd go so far as to say this is the most effective piece of engine down-sizing the car industry has yet seen. It's that good.

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