SUBARU is going lean and green, as well as cutting running costs, for owners of its popular Legacy Tourer estate model.

The most important change is the arrival of the Japanese company's next-generation Boxer diesel engine, complete with more efficient turbocharger and new exhaust-camshaft timing.

Upshot is an improvement over the outgoing model in fuel economy of more than seven per cent, to an average 49.6mpg while CO emissions are cut by up to 7.5 per cent to 149g/km.

And all Legacy Tourer diesel models now have a CO rating below 160g/km which ensures they will qualify for tax savings by the hirer of 15 per cent and 10 per cent for business users.

Performance remains unaffected, the 2.0-litre engine producing 147PS for figures of 0-62mph in 9.6 seconds with a top speed of 120mph. 

The Legacy's six-speed manual transmission, which is standard fit for diesel models, has been refined to improve its fuel efficiency, shift feel and its ease of operation and there have also been suspension upgrades.

Exterior changes are limited to smoother door mirrors, a higher-resolution rear view camera and a fresh colour - Ice Silver Metallic. 

Inside, the 2012 Legacy sports a single-CD unit featuring a large LCD display screen together with USB and iPod connectivity and steering wheel-mounted controls.

And on manual diesel models the instrument cluster now has a shift-up indicator to encourage an economical driving style.

All models feature cruise control, glass sunroof, dual-zone air-con, six-speaker sound system, Bluetooth, automatic lights and wipers and a powered driver's seat.

UK buyers now have a choice of five versions with a diesel or petrol engine and three trim levels, with prices from £26,865 for a 2.0D S model rising to £31,375 for a 2.5i SE Navplus petrol version.