Subaru’s new Boxer Diesel engine is now available in the new Forester where it is expected to account for 80 per cent of sales and eventually turn the SUV into Subaru’s best-selling model.

First introduced in the Legacy and Outback this February, the 2.0 litre, four-cylinder horizontally-opposed Boxer Diesel engine offers outstanding refinement and throttle-response plus exceptional handling thanks to its light weight and low centre-of gravity.

And in the new Boxer Diesel Forester – itself only launched in April in petrol format – the boxer diesel catapults it to the top of the class for fuel economy and low emissions. It also offers drivers the longest range of any SUV at more than 1,000 km before refuelling.

No other competitor can match the new Forester 2.0D X’s Combined 44.8 mpg nor its ultra-low 167 g/km meaning an annual Road Fund Licence of £170.

Meanwhile, the Boxer Diesel Forester’s 115.5 mph top speed and 10 second 0-60 mph time makes it one of the swiftest of SUVs while the extra engine torque over the petrol model allows a full 2,000 kg braked towing limit.

Apart from the much-applauded new engine, key improvements over the 2.0 litre petrol Forester include a new six-speed manual gearbox, uprated front suspension and firmer-feeling steering.

The new Boxer Diesel uses an advanced common-rail fuel-injection system with the fuel being pressurised at 180 MPa before being fed into the common rail. This maximises efficiency, both in terms of power, fuel consumption and emissions.

The variable nozzle turbocharger ensures the correct boost throughout the engine’s rev-range and its low centre-of gravity position under the engine and close to the catalytic converters increases environmental performance.  

The Boxer Diesel meets Euro4 emission standards thanks to oxidation catalytic converters and a particulate filter.

A new feature for the Forester is a DPF (Diesel Particulate Filter). This reduces PM (Particulate Matter) – the cause of black smoke – to the minimum.

On sale this September, the new Boxer Diesel Forester range comprises three models with their own specific trim levels – the 2.0D X at £20,295, 2.0D XC at £22,495 and 2.0D XSn at £25,495 (all on-the-road).