Volkswagen Passat

And this is just what Volkswagen has done with its new entry-level Passat. The ancient 2.0-litre 8v powerplant - which still has a home in non-turbo versions of the Golf GTI and Beetle - never felt at home in the Passat, lacking refinement and having a CO2 figure far higher than the competition.

So the German firm has swapped it for the state-of-the-art 2.0-litre 16v 130bhp unit from the Audi A4, and immediately improved the car's appeal, both on paper and the tarmac. As with all models in this sector, low emissions are a real sales advantage since the introduction of the infamous company car tax rules, and, at 206g/km, the old entry-level Passat was CO2-heavy. The new version shows a marked improvement at 194g/km, and is now comparable to more modern rivals such as the Ford Mondeo and Vauxhall Vectra.

And it's not only your wage packet which will see the benefits, either. The new engine sounds far less gruff and strained than its predecessor, while the performance is better all-round. The car now covers the 0-60mph sprint in 9.9 seconds (down from 11.2) and the top speed is up by 6mph to 130mph. This makes for far more relaxed cruising, and owners will have to stop for fuel less frequently, too - average economy is slightly improved, with the 34.9mpg offered by the new engine bettering the old model's 32.8mpg. In fact, the only real downside to the Passat 2.0 is the ΂£155 price increase. But given that side curtain airbags and an additional three-point seatbelt in the back are now fitted as standard, this seems good value to us.