Triumph GT6: the poor man's E-Type (1966–1973)

No classic GT has spent as long being underrated as the handsome, six-cylinder Triumph GT6. Built on the Spitfire platform but given a smooth 2.0-litre straight-six and a graceful fastback roof, it earned the nickname “the poor man’s E-Type” and lived up to more of the comparison than its price suggested. Its reputation was nearly ruined by a handling flaw and then rescued by a clever fix, and the result is one of the most appealing affordable classic GTs there is.

The GT6 is part of the classic Triumph range, the upmarket six-cylinder sibling of the Spitfire, slotting between the small open sports cars and the big TR roadsters.

A six-cylinder roof on a Spitfire

The GT6 arrived in 1966, designed by Giovanni Michelotti as a fastback coupe developed from his Spitfire, with roots in the aerodynamic fastback Spitfires that had raced at Le Mans. Underneath it used the Spitfire’s separate chassis and transverse-leaf rear suspension, but in place of the Spitfire’s four-cylinder engine it carried the 2.0-litre Triumph straight-six shared with the 2000 saloon and the TR5 and TR6 family. That gave it real pace and a smoothness the four-cylinder car could not match, and the long fastback with its opening rear hatch gave it the look of a scaled-down Jaguar E-Type. Around 40,926 were built at Canley over seven years.

The handling saga, and the Rotoflex fix

The GT6’s story is dominated by its rear suspension. The Mk1 inherited the Spitfire’s swing-axle layout, but the six-cylinder car’s extra weight and power made its bad habits worse: under hard cornering the rear could tuck under and change camber sharply, and the press criticised it heavily.

Triumph’s answer, on the Mk2 of 1968, is one of the better listened-to-the-critics stories in British motoring. The Mk2 gained a properly engineered rear suspension with reversed lower wishbones and flexible Rotoflex rubber driveshaft couplings, giving something close to double-wishbone geometry. It transformed the car, curing the swing-axle vices and turning the GT6 into a genuinely fine-handling GT. The Mk2 also gained a better cylinder head and more power.

The Mk3 of 1970 brought the restyled Spitfire Mk4 body with its cut-off tail and is the fastest GT6, good for around 112 mph. The one caveat for enthusiasts is that late Mk3 cars reverted to the cheaper swing-spring rear as a cost saving; it works well, but the earlier Mk2 and early Mk3 Rotoflex cars are the prized ones to drive.

Living with one

The GT6 is a more serious car to own than the Spitfire. The straight-six is wonderfully smooth and torquey and long-lived, but it leaks oil and rattles on a cold start until the oil circulates, and the whole car is heavier and more complex than the four-cylinder Spitfire. Its real weak point is the drivetrain: the differential and universal joints work hard against the six’s torque, and the Rotoflex couplings on the better cars perish over time and must be replaced in pairs. None of it is a deal-breaker, but it makes the GT6 a car to buy carefully rather than casually.

Buying guide: what to look for

The GT6 rusts in the same places as the Spitfire and a few of its own. On the body, check the structural sills and floorpans, the wheel arches, the chassis outriggers, the door bottoms, the A-posts and screen pillars, the double-skinned leading edge of the roof at the windscreen, and the panel between the rear lights, which is GT6-specific and not reproduced, making it a real headache if it has rotted. A leaking brake master cylinder strips paint off the bulkhead and starts rot beneath it.

Mechanically, listen for differential and universal-joint whine, the GT6’s drivetrain being its weakness, and check the condition of the Rotoflex couplings on the cars that have them. The six itself is durable; a spin-on oil-filter conversion cures the cold-start rattle. Parts supply is good and improving, though a few body panels are scarce, so buy on the soundness of the structure.

Where the GT6 sits in the market

The GT6 remains conspicuously cheap for what it is, and cheaper than it was three years ago. The scarce Mk1 and Mk2 lead, the plentiful Mk3 follows a few thousand behind, and overdrive is the option that earns its money on any of them. The full record, 215 recorded sales with the early cars above the common one and close to half the real value given back since 2021, is on the page covering what a GT6 sells for. For a genuinely handsome six-cylinder GT with E-Type echoes, it is one of the last real bargains.

In the wider story the GT6 is Triumph’s attempt to offer grand-touring style and six-cylinder smoothness on a budget, a cult underdog whose reputation was made and nearly unmade by the swing-axle saga and then rescued by the Rotoflex Mk2.

Owners’ clubs and parts

The Triumph Sports Six Club and Club Triumph cover the GT6 as part of the small-chassis Triumph family, with technical support and spares. Most mechanical and body parts are available new through the marque specialists, the main exception being a few GT6-specific panels, while second-hand chassis are cheap and plentiful.