The 2009 Mazda3 MPS won’t be the only car that Mazda will be debuting at the Geneva Motor Show this March, for the Japanese manufacturer has announced that it’ll be taking the wraps off yet another variant of its best-selling hatchback too.

Called the Mazda3 i-stop, this eco-friendly model combines Mazda’s proprietary stop-start system with the company’s familiar 2.0-litre MZR DISI, a combo which Mazda says can reap savings in fuel consumption of up to 12 percent during urban driving.

The i-stop system works by halting the engine with one cylinder near the top of its compression stroke. When the driver lifts off the brake to begin accelerating again the ECU then fires that cylinder’s sparkplug, igniting the compressed fuel-air mixture and thus restarting the engine.

It’s a delightfully streamlined system, and one that doesn’t require any extra starter motors, heavy-duty alternators or batteries to function. For all intents and purposes the Mazda3 i-stop is virtually the same as the garden-variety 3, except for the fact that it doesn’t idle when sitting at traffic lights.

Further details, specs and pricing have yet to be released (for instance, it’s not yet known whether a manual transmission will be offerred), however we’ll likely hear more by the time the doors open at the Geneva Motor Show on March 3. Watch this space

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