The 118d Convertible is powered by a 1,995cc single turbocharged engine producing 143hp and 300Nm of torque. This results in a zero BMW-118d-Convertibleto 62mph time of 9.5 seconds and a top speed of 129mph. Most impressive though is the 118d Convertible’s ability to record a combined consumption figure of 57.6mpg and CO2 emissions of 129g/km. This means the vehicle, courtesy of BMW’s EfficientDynamics technologies, is the most economical and least polluting convertible car in its class.