Caterham Roadsport 150: 270Bhp Per Tonne, Specs & Review

The Caterham Roadsport 150 stands as a testament to minimalist engineering, delivering exhilarating performance through its featherlight construction and punchy powertrain. This open-top roadster, rooted in the legendary Lotus Seven heritage, prioritizes driver engagement over creature comforts, making it a favorite among purists who crave an uncompromised connection to the road.

Engineering a Featherweight Champion

At the heart of the Roadsport 150’s appeal is its incredibly low kerb weight of just 550kg, achieved through a spaceframe chassis inspired by classic designs. This lightweight ethos allows a modest 150bhp engine to punch far above its weight, boasting a power-to-weight ratio of 270bhp per tonne—equivalent to a Porsche 911 GT3. Dimensions are compact: 3,380mm long, 1,115mm high, with a 2,225mm wheelbase, ensuring nimble handling in tight corners.

The chassis comes in two flavors: the traditional Series 3 (S3) for a classic feel and the wider Series V (SV) for enhanced stability and space. The SV variant stretches the wheelbase slightly and widens the track, improving high-speed composure without sacrificing the car’s playful nature.

Powertrain: Rev-Happy Ford Sigma

Power comes from a 1.6-litre Ford Sigma engine, a naturally aspirated inline-four producing 150bhp at 6,900rpm and 163Nm of torque at around 5,600rpm. This revvy unit, with DOHC and 16 valves, features multi-point fuel injection and a compression ratio of 11:1, paired with a catalytic converter for emissions compliance.

Transmission options include a crisp five- or six-speed manual gearbox, often with an open or limited-slip differential. The lightweight flywheel and short gearing keep the engine in its eager mid-range, propelling the car from 0-60mph in exactly five seconds and on to a top speed of 182km/h (113mph). Fuel tank capacity is a practical 36 litres, suitable for spirited runs without frequent stops.

Chassis and Suspension Dynamics

Suspension is a double-wishbone setup at the front with wide-track geometry for precise steering response, complemented by a De-Dion rear axle for predictable handling under load. Adjustable Bilstein dampers and anti-roll bars allow tuning for road or track use. Brakes feature uprated quad-piston calipers and ventilated front discs, providing confident stopping power despite the minimal mass.

Wheels are typically 14-inch alloys shod with grippy 185/60 R14 tyres, like Toyo R888Rs or Falken Zeix, balancing road legality with track prowess. The small-diameter Momo steering wheel offers immense feedback, with visible wheel articulation heightening the sense of involvement.

Driving Experience: Pure, Unfiltered Joy

Behind the wheel, the Roadsport 150 feels alive. The engine’s linear power delivery suits the chassis perfectly—neither overwhelming novices nor boring experts. Acceleration is explosive thanks to the stellar power-to-weight, with 0-100km/h in under five seconds. On twisty B-roads, the sharp turn-in and minimal body roll make it dance through corners, rewarding smooth inputs with neutral balance.

Wind in your hair and road imperfections telegraphed directly to your fingertips define the experience. It’s not for daily commuting—ingress/egress requires athleticism, and weather protection is rudimentary with optional full enclosures or heated windscreens. Yet for track days or canyon carving, it’s unmatched in engagement.

• Pros: Exceptional handling, blistering acceleration, ultimate driver feedback.
• Cons: Minimalist interior, weather vulnerability, high entry price for kits.

Build Options and Customization

Caterham offers the Roadsport 150 as a kit car, starting around £20,000-£30,000 excluding engine/transmission, appealing to DIY enthusiasts. Factory-built models add premium. Options include leather seats, track roll bars, immobilisers, and performance exhausts. The SV chassis provides more elbow room and boot space, ideal for longer tours.

Colors like Viper Blue with stripes add flair, while black packs and clear lenses enhance aesthetics. Anti-cavitation oil systems ensure reliability during hard driving.

Performance Benchmarks

In benchmarks, the Roadsport 150 rivals modern hot hatches despite its vintage roots. Its 270bhp/tonne ratio delivers GT3-like thrust, with turning circles aiding urban agility. Fuel economy hovers around 30-40mpg in mixed driving, impressive for the fun factor.

Ownership and Practicality

Running costs are low due to the efficient engine and tiny footprint—insurance groups are favorable for enthusiasts. Maintenance involves routine checks on the spaceframe and suspension bushes. Parts availability is strong via Caterham’s network. Seating two, it’s best for couples or solo blasts; luggage space is limited but adequate for weekends.

Emissions meet Euro standards, with the lightweight design inherently eco-friendly—no need for massive powertrains.

Who Should Buy the Roadsport 150?

This car suits track-day regulars, classic car lovers, and anyone tired of padded, disconnected modern vehicles. It’s not for families or long-haul cruisers but excels where fun per pound matters most.

Frequently Asked Questions (FAQs)

References