Vauxhall has become another manufacturer to get on the sub-120g/km CO2 bandwagon. The Corsa 1.3 CDTI 75PS has been magically revised to produce a CO2 figure of 119g/km – with a combined fuel consumption of 62.8mpg. So if you’re looking for a refined small hatchback with car tax at just £35 per year (the CO2 emissions mean the car is in road tax band B, lowering the cost of an annual disc from £115 to only £35) – should you consider this Corsa?

Well the first thing to be aware of is that this latest Corsa has grown. It used to be a small supermini and now it feels like it’s approaching the size of the Astra. Certainly the styling follows that of its big brother.

The larger proportions mean that it’s better for fitting families and family-related things inside. The five door version that we tested is best for this market – the three door version is the option for those who want a more sporty appearance.

Applying the principles of yin and yang, yes, it’s good that this new Corsa is bigger – however anything that’s bigger also tends to be heavier, and for a small diesel engine producing just 75PS, the downside is that it feels like a lot of car to get moving. Acceleration from 0 to 62 takes 13.6 seconds... and it feels like a long time. When it gets to the speed you want, and it maxes out at 101 mph, it seems fairly happy, but it’s not the most confidence-inspiring car for overtaking tractors on country roads.

And take a look at how much of the car sticks out ahead of the front wheels. Then compare that with a Mini. The Corsa actually isn’t that bad on corners for this class of car, but when contrasted with the way a Mini goes round corners, all that extra weight at the front of the car makes it feel very heavy and slow to react.

However, for the average Corsa owner, this may not be top of the list of priorities. The new Corsa does everything ‘OK’ – in the key areas such as looks, space, comfortable ride, equipment (the engine is available in Life and Club trim levels), running costs (insurance group 3) and price (£10,210) (petrol versions are cheaper). The interior is again ‘OK’ – but nothing to excite you in terms of design or quality. The silver band running up on to the top of the dashboard can make an annoying reflection in the windscreen, and the tank on our car had to be filled twice before the fuel gauge took any notice and pointed to full rather than empty.

The Corsa feels like a big car. Three and five door cars are the same size, but you only get four seats in the three door as the headroom is reduced. CD player, remote central locking and electrically adjustable door mirrors are standard across the range. The Club trim has better equipment such as more adjustment for the driver’s seat and steering wheel. With Club trim upwards you also get split-folding rear seats and a separate compartment under the boot floor.

Here at Green-Car-Guide we encourage and applaud all efforts by manufacturers to give us lower carbon cars. For small families who are sufficiently happy to drive everywhere in no rush whatsoever, then this car is a cost-effective solution – especially if lots of driving is on motorways. Unfortunately, in most cases, we just think that this may be a bridge too far down the road of sacrificing performance for that magic 119g/km of emissions for many potential owners. It runs out of steam very quickly; the 89bhp diesel may be easier to live with every day.

This doesn’t mean that Vauxhall should give up with this idea. If BMW can coax 119g/km of CO2 AND respectable performance from a 118d – admittedly at a higher price – then it should only be a matter of time before Vauxhall’s engineers can give us a 99g/km Corsa with sub 10 second 0-60 mph time...

However this car could be good news for Londoners. Because the Corsa now emits less than 120g/km of carbon dioxide, it will be exempt from London's congestion charge if Mayor Ken Livingstone's proposals are approved. This incentive, due to take effect next year, could save drivers who enter the capital daily more than £2,000 every year.

And company car owners will also benefit if they choose the 1.3-litre diesel. It falls into the new 13 per cent company car tax band which was introduced by the Chancellor for diesel models emitting less than 120g/km. The drop could save top-band earners £237 a year.

In fact, Vauxhall believes that if a corporate fleet driver was using the Corsa in London every day, they would recoup the list price of the car in tax and congestion charge savings after little more than four years.

The Corsa road test took place during the week when it never stopped raining – with the consequent floods. This car was never taken off tarmac public roads – despite the fact that the photos suggest it was driven down a river. Which throws up the interesting issue of why increasing numbers of drivers seem to feel more safe and secure in the likes of a Land Rover Freelander than a small hatchback that feels very vulnerable when faced with the increasing extremes of our changing climate. So the question is, should motor manufacturers, as well as trying to prevent climate change, also adapt the design of their products to cope more confidently with climate change? An opportunity for all those mad inventors out there to bring their amphibious cars back to market...?

Vauxhall Corsa 1.3 CDTI 75PS Club 5 door: Price £10,210