UNDOUBTABLY the best aspects of Peugeot's 406 range is the 2.0-litre turbo-diesel four-cylinder engine found in both ST sedans and wagons, both available with a five-speed manual or four-speed auto transmission. The oil-burning 406 offers a mere 82kW of peak power, but provides good torque at sensible revs, which makes for impressive round-town tractibility. Open-road performance is surprisingly spirited too, yet fuel economy remains outstanding.