Small-scale British sports car manufacturer Caterham has officially released details about its new Superlight R300 two-seater, as well as its touring-focused Roadsport 175.

As per its name, the Superlight 300 is focused on agility and minimalism - its extremely light weight of 515kg (1,135 lbs) gives the vehicle an impressive 339hp-per-tonne, a figure that betters the likes of the Mercedes McLaren SLR and the current Porsche 911 Turbo. According to Caterham, the latest Seven should be able to punch from 0-to-60mph in 4.5 seconds, courtesy of its new 2.0L Ford Duratec engine which has been tuned by Caterham Powertrain (CPT) to deliver around 175hp (130kW).

Translated through Caterham’s 6-speed gearbox, the 2.0-litre Ford powerplant is able to spin the R300’s bespoke Avon CR500-shod Superlight aluminum wheels to a top speed of 140mph.

Originally launched in 2002 and fitted with a Rover engine, the previous R300 was Caterham’s best-selling Seven, and this should remain unchanged due to the increased engine performance and chassis developments found in the latest model.

The hardcore Superlight R300 was designed primarily for track use, a fact you can check just by looking at its options list. Buyers will be able to add Stack data logging instrumentation, a dry sump oil system and a limited slip differential.

However, if a Superlight R300 is a little too hardcore then Caterham is happy to offer a more muted version - the Roadsport 175. Despite being fitted with the same chassis and engine as the Superlight R300, the new Roadsport is aimed at drivers largely focused on B-Road blasts and touring.

The Roadsport trades its more track focused features, such as lashings of carbon fibre and track-biased suspension and brakes, to come fitted with all-weather equipment and a heater as standard. Other differences to the R300 include a 5-speed gearbox with longer ratios and 14in alloy wheels.

Pricing for the Superlight R300 will start at £24,995 ($38,805) in component form and £27,995 ($43,462) for a factory built version, while prices for the Roadsport 175 start at £21,995 ($34,147) in component form and £24,995 ($38,805) for factory built.