Mazda adds stop/start to new range

Jul 6 2009 Chris Russon

Mazda adds stop/start to new range

A STOP/START version of the new Mazda3 is being introduced to improve the Japanese car maker's environmental credentials.

With CO2 emissions below 160g/km the Mazda3 i-stop is aimed directly at company car users.

Average fuel economy has been improved by 16 per cent to 41.5mpg and the car features a new two-litre direct injection petrol engine.

The stop/start system puts Mazda head to head with the likes of BMW which is now using such fuel saving technology in most of its models.

The i-stop arrangement makes its debut in the Mazda3 Sport priced from £18,025 and joins the new Mazda3 range which went on sale in the middle of May.

Developed in-house by Mazda, the stop/start system is incredibly advanced. Instead of using the starter motor alone to refire the engine, i-stop works by using energy from the combustion process.

The benefit is it keeps electrical consumption on restart to a minimum and the process is twice as fast.

Unfortunately, when compared to the BMW system, the improvements are almost unnoticeable at just 0.3 of a second.

The stop/start Mazda has two batteries, one exclusively for the i-stop, and the system is smart enough to keep the engine running if necessary.

That means the use of air conditioning or other systems which can drain the battery are not interfered with in heavy traffic.

On the road the Sport is as good to drive as any of the new Mazda3 models. It's a six-speed manual and the new engine is a normally aspirated development of the 2.3-litre turbo uses in Mazda's high performance MPS cars.

Top speed is a claimed 132mph, 0 to 60 takes 10.4 seconds and Mazda is pitching the car at driver's who don't want a trade off in performance for the sake of economy and tax benefits.

The stop/start car has CO2 emission of 159g/km, just scraping below the 160g/km capital allowance threshold.

However, while Mazda's technology is clever it has a way to go to match BMW. A rival BMW 318 with similar performance has emissions which are much lower, albeit some £3,000 more expensive.

The i-stop - it stands for idle-stop - is designed to make using the Sport more economical in city traffic by switching off the engine when the car comes to rest.

The engine restarts as soon as the clutch is depressed to start moving away.

The Sport comes fully kitted with the likes of sat nav, stability control, Bluetooth phone connection and keyless entry as standard.

There is also a ten speaker BOSE sound system and the car features a new emergency stop signalling system to alert following drivers to heavy braking.

While the stop/start arrangement is likely to make its way on to other Mazda models such as the Mondeo-sized Mazda6 it can be used only on direct injection petrol engines and not on diesels where greater savings could be achieved.