The 2027 Ariel Atom 4RR is the most powerful and expensive version of the lightweight British roadster to date. Based on the fourth-generation Atom and created to mark the model’s 25th anniversary, the road-legal 4RR produces 525 horsepower from a comprehensively reworked Honda Civic Type R–derived 2.0-liter turbocharged four-cylinder.
Ariel’s new agreement with U.S. distributor Forman Motorworks will make the company’s full range and optional equipment available to American customers through U.K. factory build slots. U.S. deliveries are planned to begin next summer, although pricing has not yet been confirmed. In the U.K., the 4RR costs £208,000; the estimated U.S. price is $325,000.
With an estimated curb weight of about 1,500 pounds, the 4RR has a formidable power-to-weight ratio. The engine produces 406 pound-feet of torque at 5,200 rpm and reaches its 525-hp peak at 8,200 rpm. Buyers can also select less aggressive engine maps producing 400 or 500 horsepower, while adjustable traction control and ABS can be configured through several stages or switched off.
The engine receives forged connecting rods and pistons, closed-deck sleeves, and a revised cylinder head with upgraded camshafts, valve springs, and guides. Ariel also fits a larger turbocharger operating at nearly 25 psi and an intercooler approximately twice the size of the unit used in the 4R. The preparation and balancing process is said to take around 100 hours.
On the road, the 4RR’s headline performance is accompanied by an unexpected level of composure. Reworked manually adjustable Öhlins dampers allow the pushrod-operated suspension to run softer, while a new aerodynamic package and 12.2-inch AP Racing brakes with four-piston calipers improve the car’s control. The setup work was overseen by racing driver and former Top Gear Stig Phil Keen.
The Atom remains highly responsive and communicates road and mechanical information with unusual clarity, but the 4RR is less unsettled by bumps, changing cambers, or midcorner throttle adjustments than earlier versions. Its six-speed sequential transmission can also be operated with relatively little drama when used with the clutch.
Performance becomes especially intense in the highest engine map. The 4RR remains progressive as boost builds, but its acceleration toward the 8,200-rpm limiter and its sharp overrun sounds underline how much more serious it is than the lower-power settings. Full-throttle clutchless upshifts add to the sense that the car is most at home on an open racetrack.
Despite that output, traction is described as exceptionally strong in dry conditions. The 255-section rear tires, Yokohama A052 track-focused rubber, compliant damping, and the rearward load from the engine help the car put its power down effectively.
Compared with an early Atom, the 4RR preserves the original’s tactile steering and directness while reducing its nervous behavior. The steering remains quick without following every surface imperfection, the balance is still adjustable with the throttle, and the powerful brakes slow the car without unsettling the front axle.
Ariel lists an estimated 0-to-60-mph time of 2.3 seconds, a 0-to-100-mph time of 5.1 seconds, a quarter-mile time of 9.0 seconds, and a top speed of 175 mph. The mid-engine, rear-wheel-drive two-seater uses a six-speed automated manual transmission and measures 138.6 inches long, 74.0 inches wide, and 44.2 inches high.
Sources: Car and Driver.