TR2 to TR5, 15 years of evolution

Although the original TR2 of 1953 shared very few components with the last of the TR5/TR250 types built in 1968, a continuous, strong, and easily identified, pedigree linked all individual cars built in those fifteen years. The original design philosophy, which was to produce a simple, rugged, and reliable 100+ MPH sports car which could be maintained by any Standard-Triumph franchise, anywhere in the world, was retained throughout.

The original TR2, built from 1953 to 1955, set all the standards for later versions of these cars, which were retained. Harry Webster's engineers produced a remarkable chassis, Walter Belgrove's body designers offered a smart semi-traditional sports car style (complete with removable side curtains and cutaway doors), while Ken Richardson's diligence helped sort out every development problem. The heart of the car was the extremely robust 90bhp/1,991cc engine, which had easily removable 'wet' cylinder liners, and was closely related to engines used in the Standard Vanguard and, indeed, in the current Ferguson tractor. Body shells were produced by Mulliners in Birmingham, and final assembly was at Standard-Triumph's Canley plant.

As expected, most TRs were always sold in the North American market, where the optional Laycock overdrive, and centre-lock wire wheels, were always popular. Changes to the body structure, which resulted in the original full-depth passenger doors being changed to a 'short door' layout, came late in 1954, while a removable hardtop option became more and more popular.

The TR3 took over from the TR2 at the end of 1955, the important changes being to provide more power (this rose from 90 to 95bhp at this time), along with a square slatted front radiator grille. Then, from late 1956, all new TR3s were equipped with front-wheel disc brakes as standard equipment, which gave the cars a performance and marketing advantage over all their rivals.

The biggest change then followed, for 1958, when the TR3A took over, this car having a modified 'wide-mouth' front style, exterior door handles and a higher level of trim and equipment. An enlarged, 2,138cc, engine became optional from 1959 (though few such cars were sold, it seems). It was this model which the American buyers really took to their hearts, for in the next four years more than 58,000 examples would be built.

Although the TR4 then came along, to replace the TR3A, in 1961, for one year only, in 1962, an interim 'old model' called the TR3B was produced, entirely for the North American market - this keeping the original 'side-curtain' style, but using the updated TR4 engine and transmission.

New style, by Michelotti
For the new TR4, Standard-Triumph not only provided a completely new body style (shaped by its consultant Giovanni Michelotti), which came complete with wind-up windows, a more roomy cockpit with face-level ventilation, and a smart optional two-piece hardtop, which had a removable roof panel. Again as an option, a canvas 'Surrey' top with a simple bracing frame could be fitted instead of this roof panel.

Although based on the earlier chassis, the TR4 frame featured wider front (by four inches) and rear (by 2.5 inches) wheel tracks, along with rack-and-pinion steering. As before, both overdrive and centre-lock wire-spoke wheels were optional extras. For this model, a 100bhp/2,138cc engine became standard equipment, though the 1,991cc engine was still available to special order: very few such cars were ever built. The TR4 also got a new all-synchromesh gearbox, which was a direct descendant of the old type, though different in many detail ways.

Although the TR4 sold very well - more than 40,000 were built in less than four years., it was then replaced by the TR4A in the spring of 1965. Although this looked virtually the same as before, it featured an entirely new type of chassis frame, complete with independent rear suspension, featuring coil springs and semi-trailing arms (this being closely related to the modern Triumph 2000 saloon, which had recently gone on sale).

For sale only in North America (the USA and Canada), Triumph marketed an 'entry-level' TR4A with a lower price tag, that car having a beam axle/leaf spring rear suspension installation. It was a success, for about 10,000 of total TR4A production (of 28,465) had this layout.

Six instead of four
The last big change in this long-running product line then followed in the autumn of 1967, when Triumph finally replaced the legendary old 'wet-liner' four cylinder by the longer, smoother and eventually more powerful 2,498cc straight-six-cylinder engine, which had already been in use on other Standard and Triumph models since 1960. Many nostalgic tears were shed over this decision, but it made sound technical sense, especially as the first exhaust emission limiting rules were being brought in, in North America: the dear old 'four' could not meet the new rules, and was in any case at the end of its development life.

Two versions of the engine, and two new models, were unveiled at the same time. For sale only in North America, the TR250 was fitted with a 104bhp version of the engine, this using twin 175CD Zenith-Stromberg carburettors. Visually, this car was identified by having transverse 'speed stripes' across the bonnet and front wings. In later years, a number of TR250s were re-imported to the UK, as used 'classics'.

For the 'Rest of the World', there was the TR5, which was fitted with a 150bhp version of the new 'six', this time with Lucas fuel injection as standard equipment. It was Britain's first fuel-injected road car, and could reach 120mph, with much fiercer acceleration than in any previous TR. Although it cost £1,212 in the UK, it was still seen as a performance bargain, and some teething trouble with the injection equipment was soon sorted out.

These twin models, however, had a very short life, for an evolution was already being planned, and the last were produced before the end of 1968. This was the point at which the newly-shaped TR6 took over from both types, this being a car which looked, and in many ways was, very different from the Michelotti-styled TR5/TR250 style which had served so well.

TR6, TR7 and TR8
From 1969, the re-styled TR6 took over from the TR5/TR250 family. Though mechanically similar to those cars, the style had been completely re-worked, with totally different front and rear ends. Over the years the design was further refined, this including as minor de-tune of the injected engine in 1973.

Then, from 1975, the all-new TR7 was introduced. Originally a fixed-head coupe with a 2-litre four-cylinder engine, and a beam rear axle, this car eventually spawned a V8-engined TR8 version too, and more derivatives would have followed if the parent company (British Leyland) had not been in such awful financial difficulties.

The last TR of all was produced in 1981, by which time nearly 210,000 TR6, TR7 and TR8 cars had been built.

Graham Robson

TR2 to TR5	Years	Basic Summaries
TR2	1953 - 1955	Original style, with 2.0-litre engine.
TR3	1955 - 1957	Style as TR2, with more power. Disc brakes for 1957
TR3A	1958 - 1961	Wide-mouth style version of TR3. Optional 2.2-litre engine
T3B	1962	TR3A style/chassis, with TR4 running gear. Sold only in North America
TR4	1961 - 1965	Wide track chassis, with brand-new style
TR4A	1965 - 1967	Re-touched TR4 style, with new chassis, and independent rear suspension. beam rear axle option for North America
TR5	1967 - 1968	Re-touched TR4A style, with new six-cylinder engine and fuel injection. Not sold in North America
TR250	-	North American version of TR5, with carburetted-engine

TR Production Figures : 1953 to 1968 These were the number of TR sports cars built at Canley (or, in the case of the TR3B, in Birmingham) in the 1953 - 1968 period
Model	UK Market	Export Market	Total
TR2	2,823	5,805	8,628
TR3	1,286	12,091	13,377
TR3A	1,896	56,340	58,236
TR3B	-	3,331	3,331
TR4	2,592	37,661	40,253
TR4A	3,075	25,390	28,465
TR5	1,161	1,786	2,947
TR250	-	8,484	8,484
Totals	12,833	150,888	163,721
Note; The TR3B and TR250 models were officially sold only in North America. The TR5 was never officially sold in North America.