Triumph GT6 (1966)Sicnag, CC BY 2.0, via Wikimedia Commons

Triumph GT6 Mk III

1966 — UK

Muscle Era (1960-1974)Sports CarBritishUnder $50k ClassicsBarn Find CandidatesSwinging Sixties
Engine1,998 cc Inline-6 OHV
Power104 hp
Torque116 lb-ft
Transmission4-speed manual with overdrive
DrivetrainRWD
Body StyleCoupe
Weight1,949 lbs
0–60 mph10.1 sec
Top Speed114 mph
Production40,926 units
Original MSRP$3,100
BrakesDisc / Drum
SuspensionIndependent, double wishbones, coil springs / Independent, swing axles (Mk I), Rotoflex (Mk III)

Triumph GT6 Mk III

The Triumph GT6 was born when Triumph dropped the 2.0-litre six-cylinder engine from the Vitesse into the Spitfire platform, added a lovely fastback roof designed by Giovanni Michelotti, and created one of Britain's most appealing small GTs. The concept was simple: take the Spitfire's nimble chassis and give it the smooth, torquey engine it deserved. The result was a car that could cruise at 110 mph with the kind of refinement that the four-cylinder Spitfire couldn't match. The inline-six pulled from low revs with creamy smoothness, the gated overdrive gave relaxed highway cruising, and the fastback body looked genuinely beautiful from every angle. Early Mk I GT6s had swing-axle rear suspension that could produce alarming handling at the limit, but this was progressively improved through the Mk II (Rotoflex couplings) and Mk III (revised geometry with lower wishbones). The Mk III, with its restyled front end, improved suspension, and best-sorted mechanicals, is the most desirable version. The GT6 competed effectively in club racing and was popular for long-distance touring. Today it offers an accessible entry into the world of classic British sports cars, with a lively community and good parts support.

$15,000 – $40,000

Rust is the main enemy — check sills, outriggers, floorpans, and rear spring mounts. Mk III is the best-handling and most practical. Engine is simple and robust. Overdrive essential for motorway use. Rotoflex doughnuts need regular replacement. Good club and parts support.

40,926 GT6 built across three marks: Mk I (1966-68, 15,818), Mk II (1968-70, 12,066), Mk III (1970-73, 13,042). Based on Spitfire platform with extended bonnet for six-cylinder.