The 4 Litre was based on the Sunbeam-Talbot 3 Litre, but used the 4086cc sidevalve six from the Humber Super Snipe with an alloy head. This meant 100bhp @ 3400rpm. Hydraulic brakes were fitted and it had independent front suspension by a transverse leaf spring. Rear suspension was by half elliptic leaf springs and a live axle.
Body styles were saloon, sports saloon, tourer, touring saloon, touring limousine and drophead coupe. 229 examples were built.