The Volvo V40 has lots of engines to choose from. Which engine should you go for? The choice of engine is the most important consideration when picking your new V40. In the simplest terms, it's best to stick to the smaller engines. If you're likely to cover lots of miles, or are buying a V40 for business use, then the efficient four-cylinder D2 diesel engine is the best option. Its 94g/km CO2 rating will keep tax bills low, while an average 78.5mpg should keep fuel costs to a minimum. The downside is it does feel a little underpowered, so it needs to be revved hard at times. Private buyers, or those covering fewer miles, are better off looking at the turbocharged 1.6-litre, four-cylinder T3 petrol engine. The five-cylinder D3 and D4 diesels are certainly faster than the D2, but all the power comes at once, especially in the more powerful of the two engines. We'd certainly avoid the automatic gearbox because it's indecisive and slow to react. The top-of-the-range petrol engine is the T4, which is a more powerful 1.6 turbo. It gives stronger performance than the T3, but costs more and isn't quite as efficient. We'd stick with the T3.