The BMW 116d EfficientDynamics Plus is a standout model in the BMW 1 Series lineup, offering a balance of efficiency and performance. It features a 1.5-litre diesel engine, which is known for its low CO2 emissions and high fuel economy. The model achieves an impressive 83.1mpg and 89g/km of CO2 emissions, making it one of the most economical cars on the market. Road tax is just 20 pounds a year because of its high efficiency capabilities per the DVLA.