The prospect of driving a prototype vehicle is always an exciting affair – and an opportunity which doesn’t come around very often. It’s a chance to get into the mind-set of the company and get a fleeting glimpse into a carmaker’s future. Anticipation is further amplified when the prototype in question just happens to be Land Rover’s first ever plug-in diesel hybrid.
First seen at the Geneva Motor Show in 2011, the Land Rover Range Rover_e, to give the vehicle its full title, is the result of the manufacturer’s involvement with the UK Government funded CABLED project. In total five prototypes have been built, all based on a standard Range Rover Sport with the production version 245PS 3.0-litre TDV6 diesel engine remaining in situ. Land Rover has coupled a 69kW electric motor to the diesel powerplant, and housed the motor and battery in the spare wheel well under the boot. Furthermore, two of the prototypes have a regenerative energy braking system, a technology which will be used by the company on a production model due in 2013.
Although slightly rough around the edges, after all this is a prototype, the hybrid Range Rover looks, drives, and feels very much like the standard production model it is based on. Acceleration is brisk and the powertrain is quiet, smooth and refined when out on the open road or when navigating tight residential streets.
Unlike some manufacturers which can bolt on a hybrid system to a standard model without too many problems, Land Rover has had to ensure that their hybrid system is fully capable of delivering four-wheel-drive full offroading capability. This means front and rear differentials, a mechanical locking centre differential and high and low ranges in the transmission. The finished result is a vehicle which has the Land Rover aptitude for steep gradients and muddy fields.
The vehicle’s environmental credentials speak for themselves – CO2 emissions come in at just 89g/km with a fuel economy figure of 85mpg, which is Toyota Auris Hybrid territory and a world away from the Range Rover Sport’s 230g/km and 32.1mpg figures. In fact, the vehicle should manage 690 miles on a single tank of diesel. Land Rover has employed a parallel hybrid system coupled to a standard eight-speed ZF automatic transmission, and although it can be driven on electric power alone for up to 20 miles, under normal driving conditions on our test drive we didn’t witness too many times when the engine wasn’t engaged. Instead, the electric motor helps to smooth out the need of using the engine; keeping the revs low even under acceleration and thus ensuring fuel is being sipped rather than guzzled.
After thousands of real world miles and five prototypes the Range Rover_e trial is now coming to the end. However, the vehicle maker is hard at work on the REEVolution project which will see them develop a Jaguar XJ hybrid in 2013. Fascinatingly, the electric motor technology will be coupled to a petrol engine, confirming the flexibility of the system the engineers worked on in the Range_e. The REEVolution project includes Jaguar Land Rover, Nissan, Axeon, and Lotus and is part Government funded with a total funding commitment of £20m being invested in low carbon premium vehicle technology.
Land Rover has made a commitment of releasing its first production hybrid by the end of next year. What this model will actually look like, whether it will be based on an existing model, and the cost is, as yet, unknown. What we do know is that unlike the Range Rover_e prototype the production Land Rover hybrid will not be a plug-in.
Although our test drive in the Range Rover_e was over all too soon it is clear that the hybrid system employed works well and enables a large and heavy vehicle to have supermini-like CO2 emissions and fuel economy, without compromising performance. When the final production version does appear the proof in the pudding will be how it compares offroad to its siblings, however all the signs point to it being the world’s first fully capable 4WD hybrid diesel.
