Diesel adds to Subaru legacy

By Michael Moroney

It's finally here. Subaru has a car with a dieselengine - and it's been worth the wait.

It's been a long time coming and has been on the wanted list of rural drivers down through the years - a diesel-powered Subaru. The Japanese manufacturer has gone the home-grown route with this new offering, combining new and economical power with a car range that has been well-regarded for its all-wheel-drive capability. Subaru drivers have been asking for it for years; it has been the single feature that has deterred many rural-based drivers from taking the plunge towards the brand. This new diesel engine is different and shows its performance ability. I took the new Subaru Legacy saloon model on the road for a recent test drive and came away well-impressed.

Subaru has adapted its flat or Boxer-style engine design to diesel power, tapping as much umph and a lot more torque from the diesel design than its equivalent petrol model. The Boxer engine is proven in petrol power - now it has to deliver a similar performance when fuelled with diesel.

To explain the difference between conventional and flat or Boxer engines as simply as possible, it is necessary to understand that most engines use pistons that move in a vertical way - up and down - to generate power. With the Subaru Boxer engine, there are two pistons on each side of a horizontal engine, giving a compact power unit.

Subaru still packs in the engine capacity in cc terms into the new unit. The engine is marginally bigger than the 2.0-litre petrol model and has a longer stroke.

Long-stroke engines are classically diesel and always give more torque and pulling power. And that's certainly the case with the Boxer diesel engine. The torque output is 70% greater than the petrol equivalent. That converts into good acceleration and good pulling power. This high pulling power gives the Legacy a towing rating of 1.7 tonnes with a braked trailer - that's among the highest figures for a saloon car, well ahead of the Ford Mondeo, but still not as high as the Volkswagen Passat performance.

Subaru has a reputation for performance, mainly linked to the Impreza, but that's not lost on the new Legacy diesel. The engine delivers an acceleration performance that beats its equivalent petrol model. The 0 to 100km/hr rating is just 8.7 seconds - a second faster than the petrol-powered Legacy. It's also much quicker than the competition, including the BMW 318d.

And the Legacy achieves this with the addition of an all-wheel-drive (AWD) system under the body. This extra drive system claims to give the car more stability in difficult road conditions. It will help on a greasy field surface and no doubt has towing benefits too, as well as improved road-holding in difficult conditions. The car drives well with a good feeling of power when needed. The five-speed gearbox is an obvious match for the new diesel engine. Initially I thought that a sixth gear would be a bonus but not so; the engine seemed to be able to cope well with changing road conditions.

The AWD system does not add too much weight to the Legacy, which weighs in at 1460kg. That figure makes it lighter than some of the competition. This lighter weight is achieved by a number of features, including the frameless door windows. The weight of the car also enhances its economy figures and ensures it can achieve a good pace. In economy terms, the Legacy is a thrifty unit, delivering a rating of 5.6 litres per 100km (50.6mpg) in the combined cycle. That's a match for the new 1.6-litre turbo-diesel engine fitted to the Citroen C5 and Peugeot 407, while having far better acceleration. While it's not the best in the class in terms of economy - that title is reserved for the BMW 318d - it's still near the top. This performance converts to a relatively low CO2 figure of 148g/km, putting it into Band C of the new car tax system with a relatively low annual tax figure of €290.

The Legacy comes with a good specification level. The safety package includes active front head-restraints, dual-stage front airbags, head- and chest-protecting side airbags, curtain airbags and ABS with EBD. What was missing was electronic stability control (ESP) - not that I needed it but it is becoming a standard feature on many other cars, especially those with all-wheel-drive. Subaru will claim that the low-centre-of-gravity engine preserves the car's stability and there is a measure of fact in that.

With a list price of €29,995 (stg£19,995 in Northern Ireland) before delivery charges, the Subaru Legacy diesel is placed at the value end of the market. In power and economy terms, the diesel has been worth the wait. The same engine is now available in the Subaru Forester - a more practical and spacious farming 4x4 estate car, while the Legacy is competitive, economical and worth a listing among your new diesel car options.