If this winter is anything like the last few, four-wheel drive might be the only way to get around. Lots of car makers have four-wheel drive models in their ranges but one of the few makes to concentrate almost exclusively on all-drive models is Subaru. The Japanese brand's biggest seller is the Forester, which has just been treated to new engines to improve efficiency and reduce running costs.

The 2.0-litre FB series petrol engine is all-new, but it has the same flat-four layout – with the cylinders arranged horizontally rather than vertically – as the engine it replaces. It's an unusual layout, but one which has important technical advantages – it means the engine is better-balanced and therefore spins more smoothly, and it keeps the centre of gravity of the car low to improve handling. Subaru says the new motor is substantially more economical than its predecessor, generates less CO2, and has been designed for greater low-speed pulling power. But this is still an engine that gives its best when worked hard, though it starts to sound raucous if you explore the top end of the rev range.

The alternative is a revised version of Subaru's 2.0-litre Boxer diesel, another flat-four unit. Though it has slightly less power than the petrol engine (145bhp versus 148bhp) it generates a lot more torque (258lbft versus 145lbft) and it's a lot more flexible, pulling convincingly from 1750rpm and revving smoothly right up to the 4700rpm limit. That makes the diesel convincingly quicker on the road, and it's easier and more relaxing to drive, too.

Light, direct steering and a high driving position coupled to good visibility mean the Forester feels small and wieldy on the road, as happy winding along a country lane as it is navigating the urban jungle. In town or out of it the supple suspension and 55-series tyres smoothe out the worst of rippled and pot-holed roads, and there is automatic self-levelling as standard at the rear. This keeps the Forester level even if the decent-sized and conveniently squarish boot is carrying a heavy load, or when towing a nose-heavy trailer. That and the permanent four-wheel drive system should make the Forester a very effective tow car, particularly with the torque-rich diesel engine.

In diesel form, at least, the Forester makes a lot of sense if you need estate car space, reasonable refinement and traction that'll deal with a muddy field – or an icy winter.