The Triumph TR3 is a sports car produced between 1955 and 1962 by Standard-Triumph in England. The facelifted variant, popularly but unofficially known as the TR3A, entered production in 1957 and the final version, unofficially the TR3B, was produced in 1962 Although the car was usually supplied as an open two-seater, an occasional rear seat and bolt-on steel hard top were available as extras.
The car was powered by a 1991 cc straight-4 OHV engine initially producing 95 bhp, an increase of 5 hp over the TR2 thanks to the larger SU-H6 carburettors fitted. This was later increased to 100 bhp at 5000 rpm by the addition of a "high port" cylinder head and enlarged manifold. The four-speed manual gearbox could be supplemented by an overdrive unit on the top three ratios, electrically operated and controlled by a switch on the dash. In 1956 the front brakes were changed from drums to discs, the TR3 thus becoming the first series production car to be so fitted.
The suspension was by double A-arms, manganese bronze trunnion, coil springs and tube shocks at the front, optional anti-roll bar, and with worm and peg steering. Unlike MG’s of the same period, the steering mechanism and linkage had considerable play and friction, which increased with wear.
The rear was conventional leaf springs, with solid axle and lever arm dampers, except that the (box) frame rails were slung under the axle. The wheels were 15-inches in diameter and 4.5 inches wide (increased from 4 inches after the first few TR2’s), with 48-spoke wire wheels optional. Wire wheels were usually painted, either body colour or Argent (silver), but matt chrome and bright chrome were also available. The front disc or drum brakes and rear drums had no servo assistance.
The TR3 is a true roadster, designed for sunny weather but with removable rain protection. It has a convertible hood that snaps on and off and removable side curtains, allowing very low doors with padding for the driver's arm to rest on. There are holes in the floor, with rubber plugs, so that the originally supplied jack might be used from inside the car, as did the Jaguar XK120. The optional heater was poor and the shut-off valve was under the bonnet.