Vauxhall Tigra Sport CDTI Sport a/c

A 69bhp 1.3-litre engine developed with Fiat makes the range-topping Tigra the most economical car in its class. Returning a huge 61.4mpg on the combined cycle, it will be cheap for even high-mileage drivers to run. What's more, with its 124g/km CO2 emissions and compliance with Euro IV regulations, the car makes sense for tax-conscious company drivers.

Nipping in and out of traffic with the roof down, you are hard-pushed to tell what is under the bonnet. As with many oil-burning cabrios, the wind noise drowns out the clatter of the diesel motor in all but low-speed manoeuvres.

With the Tigra in coupί¿½ guise, the engine sound becomes more of an issue, but drivers are likely to be even more frustrated by the performance. An epic 15.5-second 0-60mph time highlights the sluggish pace, but the Vauxhall still keeps up with city traffic thanks to decent mid-range acceleration.

Our range-topping Sport was fitted with air-con, and is priced at ΂£15,845. That's ΂£845 more than the equivalent 1.4-litre Tigra - but whether it proves to be good value depends on your mileage.