Adding the fuel saving technology could add up to £400 to the price of the car but only reduce CO2 emissions by four per cent on a car which already qualifies for free emissions-based road tax in the UK.
Stop-start is increasingly offered as a standard option on new cars because it helps drivers save fuel and reduces CO2 emissions by turning the engine off when the car is stationary, for example in busy traffic.
The technology will instantly turn the engine back on when the accelerator is pressed and Citroen has been developing new ‘e-boosters’ which save energy when the car brakes to offer more efficient and quicker engine restarts.
However, the tiny Citroen C1, an updated city car set to go on sale in spring 2012, will not include the technology because its small, efficient engines are green enough.
The Citroen C1 comes with the 1.0-litre three-cylinder petrol engine which delivers CO2 emissions of 99g/km. This falls into Band A of UK Vehicle Excise Duty (VED) and as a result owners will pay nothing (apart from a small administration fee).
Francois Dabadie, C1 product manager, said: “Adding £400 to an £8,000 car to get an extra four to 10 grams off the emissions isn’t worth it in my opinion. It’s a price-sensitive car,” he said.
However, the car will get Bluetooth for the first time and an electronic gearbox with steering-wheel mounted paddle shift.
The new Citroen C1 will beat the almost identical Peugeot 107 to market with a launch planned for April 2011. Prices will start from around £8,000 in the UK.