Triumph TR4 vs TR5

Rimmer's production table counts 58,236 TR3As, 2,947 TR5s and 8,484 TR250s, and 3,331 of the stop-gap TR3B of 1962, which put the TR4's gearbox, and on all but the first few hundred cars its engine, into the TR3A's body; the TR4's and the TR4A's totals are in the line-up. The last TR4A and the first TR250, CD1, were built on the same day, 11 July 1967, and the TR5 and TR250 ended on 19 September 1968, when the TR6 took their place.⁠source 2​source 4​source 5​source 1​source 3​source 6

The body changed completely: Michelotti's design brought wind-up windows, face-level vents, a curved windscreen (windshield) fixed to the body, a front-hinged bonnet (hood) and more room in the boot (trunk). Underneath, the changes were few: the tracks widened, the frame's side members were stiffened and the damper settings softened, the steering became rack and pinion, and first gear gained synchromesh, Car and Driver reported. Standard now was the larger engine that TR3A buyers had had to order as an option.

Much stayed. The frame kept its design and its wheelbase, the front suspension its wishbones and coil springs, and the back its live axle on leaf springs with lever-arm dampers. The front brakes were discs, as before. Of the engine, Car and Driver reported that only the bore and the compression changed, the stroke, head, ports and camshaft staying as they were, and the first TR4s even had seats of the TR3's pattern.

The new car was heavier and, Ate Up With Motor writes, "no faster than the TR3A": the extra power was spent on a slightly larger frontal area and more weight, by an amount the sources dispute; the TR4 page gives their figures. It rode and handled better. Car and Driver's Dennis May found "all the old directness and immediacy of response without the TR-3's characteristic twitchiness", and Bill Boddy of Motor Sport, looking back on 1961, "a softer, less 'hoppy' ride than its famous predecessor". It cost £51 more than the last TR3A before tax, and $174 more in America, by Ate Up With Motor's reckoning. Only in America did the TR3A's body carry on, through 1962, as the TR3B, because the distributors were unsure of the new car.⁠source 1​source 7​source 2​source 8​source 9​source 3​source 10

The TR4A of 1965 kept the TR4's body shell, doors, windscreen and boot, its engine and its gearbox, and changed what lay beneath: a new frame on the old wheelbase, with the rear wheels sprung independently, though the North American base model stayed on a live axle. The front suspension gained travel, the steering was slowed, and a new manifold and exhaust added a little power. It was heavier too, by about 50 kg (112 lb) on the factory's figures that Ate Up With Motor quotes. The TR4A's new face, cabin and hood (soft top) are described on the TR4A page.⁠source 3​source 11​source 12​source 2

By 1967 the TR4A was, in Ate Up With Motor's words, "no longer the screaming bargain it had once been. To remain competitive, it would need more power." The German TR Register says Standard-Triumph decided in 1965 to end the era of the wet-liner four, and that the new car was called Wasp inside the works. America's new rules on emissions settled it:

The new engine was the Triumph 2000's six, its stroke lengthened from 76 to 95 mm. The TR5 had Lucas fuel injection and was sold everywhere but North America; the TR250, for North America only, had twin Stromberg carburettors and a milder camshaft, and was never fuel-injected. Both kept the TR4A's body almost unchanged, the German guide says, with smaller rear lamps under the boot lid and inner wings shaped for the six; Robson adds the TR250's stripes across the nose. The frame and the independent rear suspension stayed, with radial tyres and servo-assisted brakes. G. William Krause writes that the TR5 weighed "only 28 pounds more than the 4A", and found the TR250 smoother and more tractable than the four but disappointing in power.

The six cost more: the TR250 was over $300 dearer than a TR4A IRS in America, Ate Up With Motor notes. Motor Sport, testing a TR5 PI in August 1968, found that it "has its imperfections, but is a vast improvement over the immediately preceding TR4A".

No source read ranks them: the choice is a buyer's. An insurer's guide of 2024 finds "a purity about" the TR4 and a more civilised ride and handling in the TR4A, and the six-cylinder cars have much more power. The TR Register's guide holds that the frames up to the TR4's were the strongest of all, and that the six-cylinder cars suffer more from rust in the rear of the frame than the TR4A does. The buying guide sets out what to check.⁠source 16​source 17