Caterham Seven Roadsport 125 CAR review

Nothing looks particularly different here. Where’s the change?

This year heralds the 50th anniversary of the Seven. Besides making a cluster of special edition livery paint-schemed cars, the Roadsport has principally got the same clothes - but a new heart and improved bone marrow. Caterham is celebrating the birthday by binning the Rover-derived K-series engine after 15 years of faithful service. It's getting long in the tooth now, they're no longer built and the stockpile built up since Longbridge went belly-up has finally run out. Lotus, too, has abandoned the K-series for Toyota lumps, remember. The newer block on the block for their lower-capacity models such as this Roadsport is Ford’s Sigma 1.6-litre 16-valve four-cylinder engine. It's more usually seen in the Fiesta, Focus and C-Max.

Will the K-series under the bonnet be missed?

Not really, although for the 2007 season every Caterham racing in the one-make academy will still run them for homologation purposes. We'll remember the K-series for its clattery top-end and need to be revved into orbit for optimum power. Despite being the same displacement, the EU4-spec emission-friendly Sigma engine is quieter and pulls harder from lower down. Thanks to Caterham’s bespoke ECU brainwash, the Sigma pushes out 125bhp and feels like a bigger-capacity motor that doesn’t have to try as hard as the old K-series.