Last October we replaced our 10-year-old Nissan Micra 1.3 automatic under the scrappage scheme, buying the new equivalent Micra 1.4 automatic. Comparing the brochures and specifications for the two cars, I noted that the official tests showed improved fuel consumption figures for the new car. However, the new car is using considerably more fuel than the old one. Can you suggest any reason why? I am not aware that I drive the new car any differently to the old one. It has a 4-speed auto gearbox, which in my view is vastly inferior to the old CVT and the car is fitted with 16 inch 185/50 tyres. Considering its performance (sufficient for my needs but modest by modern standards) its stated CO2 emissions seem high. The old car returned 47mpg overall whilst I am lucky to get more than 41mpg from the new one. There was a very marginal improvement in fuel economy as the engine of the first car loosened up but this was a tiny fraction of the difference in fuel consumption I’m seeing. The new car runs nicely and I’m not aware of any problem with the engine but I wonder why it’s using so much fuel. I’m not trying to compare the fuel consumption I achieve with the theoretical figures in the brochure, just the difference between the two cars.