It has one of the biggest batteries of any plug-in hybrid and it’s also one of the quickest.

BMW decided it was wise to pair its 3-liter turbocharged straight-six with an electric motor and quite a big battery in order to create the X5 45e. The result is a plug-in hybrid SUV with a really usable range which it blends with excellent pace.

Harry Metcalfe tested it out in the UK and arrived at some interesting conclusions. Firstly, he praises its remarkably long range on battery power alone - BMW claims its 24 kWh battery pack allows it to travel purely on electricity for up to 54 miles and even if it can’t quite match that in real-world driving conditions, it can still provide over 40 miles of electric driving.

Once the battery is close to running out of juice, the X5 45e fires up its 286 horsepower gasoline engine that, based on this review, isn’t especially economical. Whenever it is on, it really drags efficiency down and if you want to make use of the vehicle's impressive performance, which you do because the X5 is renowned for being fun to drive.

However, with an extra 660 pounds (300 kilograms) added weight from the batteries and motor (which take up the space where the folding third row of seats would have been, so it’s not available on this powertrain version), it’s not quite as nimble as the regular non-plug-in X5.

There’s still a lot to like about the X5 45e, a unique proposition in the luxury plug-in hybrid SUV segment. It has plenty of luxury, performance and, if you keep the battery topped up, efficiency as well. Mind you, the battery can only be charged at 3.7 kW, so if it’s flat, you will essentially have to wait for it to replenish overnight.