The 4 Series uses a variety of engines from the 3 Series range. These stretch from the entry-level four-cylinder diesel in the 420d right up to the potent six-cylinder petrol turbo in the 440i and M4.
The 420d, which has the broadest appeal, is swift and its engine revs keenly for a diesel, with good flexibility for when you need a quick surge of power to overtake. The turbocharged 3.0-litre petrol in the 440i pulls strongly from very low revs all the way through to 7000rpm; it feels extremely quick and makes overtaking effortless.
If you need a high-performance diesel then the 4 Series has two capable candidates in the 430d and the 435d, but the latter is available only with four-wheel drive.
The only engine to avoid is the basic 420i petrol, which revs quickly enough but simply can’t match the in-gear response of the diesels; it has to be worked hard to make reasonable progress.
The pinnacle of the range is the high-performance M4. It uses a twin-turbo straight-six engine with more than 400bhp, can go from 0-62mph in close to four seconds and has a huge number of bespoke parts to shave its weight and improve its handling.