BMW is confident of producing a 3-series model which would be exempt from the emissions based London congestion charge.The current 318d produces only 123g/km of CO2, and BMW are convinced they can meet the technical challenge of finding the 3g/km they need to beat the charge. They have already succeeded in altering the X5 3.0d to produce less than the 225g/km upper limit – conceivably saving a consistent commuter well over £3000 a year under the new system.From 27 October, any car driving into the centre of London that omits more than 120g/km of CO2 will be required to pay the £8 daily rate, while those beneath the threshold will be exempt. Cars producing more than 225g/km will face a £25 fee for entering the capital.The other financial benefit of cutting emissions is a reduction in Vehicle Excise Duty bills. Owners of the X5 3.0d already pay £205 instead of £300 – a 3-series model emitting less than 120g/km would cost just £35 a year to tax in Band B.BMW actually produces a model frugal enough to qualify for this category already – the three and five-door 118d. Recent recipient of World Green Car of the Year at the New York International Auto Show, the 118d uses BMW’s EfficientDynamics technology, such as Brake Energy Regeneration and Auto Stop Start, to produce CO2 emissions of just 119g/km.