| First Drive | Berlin, Germany | Mazda3 2.0 Sport with i-stop |

Mazda has joined the stop-start eco revolution with its 3 hatchback. The aim is to reduce emissions and increase economy, in the bid to enhance the mid-sized Mazda's appeal to company car drivers. That's the goal, but does it hit the target?

In the Metal

From the outside, there's nothing to give away the i-stop version of the Mazda3 from the other cars in the range. It has the same crisp styling and five-door hatch or four-door saloon styling. On the inside, the giveaway is the six-speed manual gearbox, which has not been available in 2.0-litre models before as they have come with an automatic until now. Otherwise, the only clues to the i-stop model are the dashboard light to tell the driver the i-stop is engaged and a small button used to disengage the system should the driver not want to use it. As for the rest of the cabin, it's the same sturdily built, spacious interior as in other Mazda3s, though it's not as quirkily appealing as a Honda Civic's.

What you get for your Money

In top spec Sport form, the i-stop version of the Mazda3 comes with a 2.0-litre, 148bhp petrol engine. For the time being, this will be the only powerplant option, though Mazda says the stop-start technology will reach across its whole range from 2011. The Sport comes in hatch or saloon body styles for the same price and includes climate control, electric windows all round, cruise control, six airbags, rear parking sensors and 17-inch alloy wheels, so it's on a par with other small hatches that cost the same.

The i-stop technology included with this car is all-new from Mazda and its big claim to fame is that the engine restarts in half the time of any rival system. The Mazda's engine goes from off to on in 0.35 seconds thanks to a re-jigged starter motor and new alternator that lines up the pistons for optimum restarting. Mazda has also introduced direct injection for this engine to help with rapid restarting.

Driving it

There are two very separate elements on test here, as far as we're concerned. The first is the way the Mazda3 drives, which is simply not as well as a number of its core rivals. The ride is just too firm and lumpy to work well on UK roads, though the 3 handles and steers well. There's also not as much shove as we'd expect of a 2.0-litre engine in such a small car and more road noise than we'd like makes itself heard in the cabin. On the upside, the six-speed manual has a quick, short-gaited shift.

More importantly for this test is the i-stop technology. On this front, Mazda has got it right. Roll up to a set of lights or traffic jam, dip the clutch, slide the gear lever into neutral and then release the clutch and the engine switches off with no drama. Dip the clutch again and the engine immediately restarts with just as little fuss. It quickly becomes an unconscious set of movements to use the i-stop and there are no concerns about holding up traffic behind or being left floundering at the lights.

We reckon Mazda has one of the best stop-start systems in i-stop, it's just a shame the Mazda3 2.0 Sport is not the best car to showcase its talents. The 2.0-litre petrol unit may offer greater gains than would be seen with a small diesel-engined supermini with stop-start, but 19 percent saving in carbon dioxide emissions over the previous generation 2.0 Sport model is much less impressive when you consider the i-stop's 159g/km is bettered by a number of rivals. That means no saving on road tax and only minimal savings for company car drivers looking to reduce their benefit in kind payments. The boost in combined economy to 41.5mpg is welcome, but again there are rivals that don't have a stop-start system that offer better economy for less cash, especially if you opt for a smaller petrol or a diesel version.

Worth Noting

There are a number of circumstances when i-stop will come into play and we seemed to experience a few of them when we thought the car would and should have switched off the engine. If the car's climate control senses the cabin temperature has gone up or down by more than 2.5-degrees from that requested, the engine will continue to run when the car is at a halt. Also, if you select full blast from the ventilation or turn the air conditioning to full chill, the i-stop won't kick in, as the system won't interfere with the car possibly being defrosted or cooled at the start of a journey. Equally, the engine won't restart by dipping the clutch if the bonnet is opened, the driver's seatbelt unclipped or the doors opened. This is a safety measure and the car will have to be restarted using the ignition button on the dash.

Summary

Mazda has come up with a very quick and slick version of the stop-start technology that we are becoming increasingly familiar with. It's easy to use, quick to act and makes useful gains in economy and emissions. However, there's a 'but' a-coming and here it is: the 2.0 Sport is not the best version of Mazda's small hatch. At £18,025 for the hatch or saloon, it's just too pricey and the savings in economy and emissions are not significant enough to offset that to make this particular version of the 3 attractive to business drivers. When the i-stop technology arrives in smaller engined and diesel versions of the 3 and other Mazda models, we think it will come of age.