Very good. The ability of the high-tech driveline to overcome the additional weight brought on by the electric motor and battery pack is evident from the outset.
Provided there is sufficient charge in the battery, the initial movement from standstill is achieved on the electric motor alone. However, it doesn’t take too much of a nudge on the throttle before the petrol engine chimes in to strengthen the initial acceleration. Together, they provide the X5 eDrive with thoroughly convincing step off and in-gear performance.
Despite weighing in the region of 2300kg, it accelerates with all the enthusiasm of the 2145kg X5 xDrive35i on a pegged throttle, as evidenced by a claimed 0-62mph time that BMW puts at "under 7.0sec". With drive channelled permanently to all four wheels via an electro-mechanical multi-plate clutch and an electronically controlled torque vectoring system, traction was never in doubt in the early prototype we drove.
Drive at a steady pace and the X5 eDrive impresses with effortless qualities. Despite our limited time behind the wheel, there is little doubt that it will probably be a decent long-distance proposition, aided by subdued driveline noise and silken gearbox traits.
An energy management system allows the driver to choose between three different driving modes: Eco Pro, Comfort and Sport.
In Eco Pro mode the electric motor plays a largely passive role during hybrid running without the ability to boost performance, while a coasting function is activated when you back away from the throttle to decouple the combustion engine from the gearbox to reduce mechanical drag and extend momentum. In the default Comfort mode the electric motor is used to boost performance when required, with a recuperation function activated to recover kinetic energy on a trailing throttle. In Sport mode, both the electric motor and combustion engine are continuously engaged, while the action of the recuperation system is made more aggressive with added retardation for additional energy recovery.
A button on the centre console also allows you to switch to pure electric mode – but only for a limited distance. BMW claims a zero-emission range of up to 18 miles on a fully charged battery at speeds up to a limited 75mph. It doesn’t sound like much. However, internal BMW studies reveal up to 80 per cent of journeys undertaken by existing X5 owners are of less than 18 miles, suggesting it will be more than enough for the majority of prospective customers.
In electric mode, the X5 eDrive is terrifically smooth and compellingly swift. The silent qualities of the electric motor tend to amplify tyre roar, but overall refinement is excellent. Despite the relatively low levels of power and torque, the electric motor also propels the big BMW in creditable fashion, offering plenty of shove from a standstill and a highly flexible delivery at typical urban speeds.