TR4: The Michelotti Style
With the same “Look” and the same philosophy used over the last 8 years the sales figures declined. Something new had to happen. The redesigned bodywork was the result of the Italian designer Giovanni Michelotti. It offered more comfort, more space and had wind down windows. The boot compartment was distinctly larger. In comparison to the previous models the mechanical changes consisted of an increased track width for both front and rear suspensions, a strengthened chassis, rack and pinion steering and a synchronized gearbox. The Standard engine had a bore and stroke of 86mm and 92mm with a capacity of 2138 cc and produced 100 PS. There still was an option of an engine with 1991 cc. Likewise Triumph offered an Overdrive, Spoked wheels and a 2 piece hardtop named “Surrey Top”. It consisted of a fixed screwed Panorama rear window and 2 replaceable roof top parts made of metal or folding top fabric. Porsche used this idea later on and named it “Targa”. The TR4 also offered the possibility of fitting Safety belts. In the beginning the sales figures were good, even though the TR4 had no more performance than the TR3A.
From August 1961 till January 1965 40’253 cars were manufactured.
TR4A: The comfort of Independent Suspension
The design of the TR4A had not changed very much to the TR4, simply a new radiator grill, indicators and chrome moldings on the front wings, a wood grained Dash and some decorative parts were added here and there. But what was noticeable was the rear suspension. In 1965 the chassis was completely reworked. The rear wheels now had coil springs and independent rear suspension (IRS). With all round IRS suddenly the competition looked very out of date. Due to reasons of cost, the TR4A cars destined for the USA retained their old rigid rear axle and leaf springs. Under the bonnet, the engine with the same capacity of 2138cc with the addition of twin Stromberg carburetors and a new exhaust system now developed 105 PS at 4’700 RPM. The maximum speed reached 160 Km/h. The Overdrive, spoked wheels and the “Surrey Top” remained available as an optional extra. On the 2nd August 1967 after being in production for 14 years the last TR with a 4 cylinder engine left the Factory.
From January 1965 till August 1967 28’465 cars were manufactured.