While hybrids, electric, LPG, CNG and hydrogen are all being mooted as possible alternatives to diesel power in the future the reality is we're still 99% reliant on diesel technology, with no creditable substitute in sight.

So a shaving here and an improvement there all adds up.

And it's this approach that's behind Mercedes' ECO-Start. Available on its Sprinter, the system turns off the engine when the vehicle becomes stationary and in neutral with the clutch depressed, then restarts it when the clutch is engaged ready to move off.

Claimed to save up to 10% in fuel consumption when operated in the urban environment, where stop/starting is commonplace due to traffic lights and jams, it costs £545 (though this reduces to £250 when air-con is specced due to sharing of components) and is available on all four-cylinder manual versions.

So do we like it? Well yes. When used in the correct environment with the appropriate driver training then it will noticeably reduce CO2 output and just as importantly, save you cash.

Of course it's not for everyone. Those flying down motorways and A-roads will find the number of times it's engaged in a day are negligible, and therefore deem it irrelevant. But pick your application wisely and it makes sense.

Furthermore, as it's fitted to a Mercedes you shouldn't have to worry about it not starting up again one day (predictably when sat in the world's longest traffic jam), and that also means it'll be cost effective to run over the lifetime.

And drivers will also like it due to the spacious and well finished cabin that will help to blot out that traffic hell.

If you want niggles then the engine doesn't quite match the rest of the van's quality while the gearshift can be a little resistant when cold.

But step back and assess the Sprinter ECO-Start as a whole and it's hard to ignore its potential and the vehicle's all-round class.