If you want to avoid diesel yet desire efficiency there's the plug-in hybrid 530e. It's a punchy performer, offering a combined 288bhp from its four-cylinder petrol engine and electric motor, which is enough for 0-62mph in 6.1sec. On top of that, the electric-only range is up to 35 miles and, while it's a lot less rapid running on the electric motor alone, it'll still power you up to motorway speeds relatively easily. Just make sure you can keep the battery charged because if you just run it on the petrol engine you'll find it hard to get the fuel economy above 30mpg. This is a great option for company car drivers because the tax breaks make it seriously cheap to run.