While the 620R offers little in the way of creature comforts, the S pack which turns it into a 620S provides basic roadgoing features, including a full windscreen, hood and side screens.
A larger fuel tank improves the range of the 620S, while luggage space is also increased to aid daily-driving appeal. The 620S is also the first Caterham model to be offered with heated seats; heated carbon seats are a £995 cost option.
The S pack also brings a more road-friendly suspension set-up, while the limited-slip differential and brake master cylinder of the 620R remain. For added comfort, road-friendly 15in wheels with different tyres replace the 13in wheels of the 620R.
The 620S shares the 620R's supercharged four-cylinder 310bhp Ford Duratec engine, but it is linked to a five-speed manual gearbox, in place of the six-speed sequential transmission used on the 620R. A top speed of 145mph is quoted, and 0-60mph is dispatched in 3.4 seconds aided by a power-to-weight ratio of 508bhp per tonne.