TriumphSpitfire

Triumph Spitfire Mk4

The Spitfire of 1970–74, Michelotti's restyle for a new decade: a short tail like the Stag's, a cleaner nose and, underneath, the swing spring that tamed the swing axle. Triumph called it the Mk IV; it is also written Mark 4, Mk4 or MkIV.

A dark green Spitfire Mk IV with its hood folded, tan seats and silver wheels, parked against a weathered stone wall.
A Spitfire Mk IV in Morges, Switzerland, in October 2012, its bonnet smooth along the tops of the wings.Akela NDE, CC BY-SA 2.0 fr

Walk round to the back of a Mk IV first. The tail is cut off short, in the manner of Triumph's Stag, and the bumper wraps round its corners. Giovanni Michelotti, who had styled the first Spitfire, reshaped it for the 1970s. The Mk IV was announced in October 1970 and built at Canley from November 1970 until late 1974 (December, in Canley Classics' table), when the Spitfire 1500 took its place in the same body.

Under the new skin, a "swing spring" tamed the swing axle's habit of tucking a rear wheel under and first gear gained synchromesh; inside, the dials moved to face the driver. On paper it had less power than the Mk III, which is the root of a myth: that Triumph detuned it.⁠1​2​3​4​5​6​7

What changed

A red Spitfire Mk IV in exact side profile, hood folded, parked at a kerb before a planted bed.
The Mk IV restyle in profile, its tail cut off short, on a red car with the 'Spitfire IV' script on its rear wing, at a kerb in West Auckland, New Zealand, in December 2014.GPS 56 from New Zealand, CC BY 2.0

The Triumph Sports Six Club says the restyle took many of its cues from the Stag, then newly launched, and that only the sills (rocker panels) and the door skins survived from the Mk III. Bill Boddy, who tested a Mk IV for Motor Sport in January 1971, counted the rest: the new tail, a smoother bonnet (hood), wheel arches flared outwards and door handles recessed into the doors.

Inside, the speedometer and rev counter (tachometer) now faced the driver, set in a panel of matt black; from 1973, as the French brochure of that year shows, the panel was wood veneer, lit in green. Boddy's car had a steering lock on the ignition key, courtesy lights and two-speed wipers, and an alternator took the place of the dynamo (generator).

The engine was the Mk III's, with better manifolds. Behind it, the gearbox (transmission) at last had synchromesh on all four forward gears, and the final drive was taller.⁠3​4​2​8

Contents

The swing spring

The rear wheels still hung on swing axles, and on the earlier cars a hard corner could tuck one of them under. Triumph's answer kept the axles and changed the transverse leaf spring above them: only its bottom leaf was now clamped to the differential, the leaves above it were free to pivot on a central bolt, and the anti-roll (sway) bar at the front was made thicker. Canley Classics, which explains the arrangement, adds that it was no new idea:

The solution developed by Triumph in the 1960s (though interestingly not implemented until the 70s because it was deemed 'too expensive' by the bean-counters!) is known as the 'Swing Spring'.

Canley Classics, "Swing Springs"

It worked. A Motor Sport tester tried a Mk IV at Silverstone for the November 1970 issue, and Boddy passed on that tester's verdict: the handling could no longer be faulted. Hagerty's buying guide says the square-tailed cars put the problem right and are far friendlier to drive. How the spring works, and why the Mk IV did not take the Vitesse's rear suspension, are explained in the buying guide.⁠7​4​9

A 1972 Mk IV driven on British roads, with its swing spring explained.Video: The Classic British Sports Car With a Deadly Secret - Triumph Spitfire Mk4, Number 27, 2025

Contents

Power, and the detuned myth

The charge that the Mk IV was detuned is an old one. Classic & Sports Car's A–Z regrets "a slightly de-tuned engine (disappointingly)", and Wikipedia says the engine was detuned to meet emission rules. The two cars' power figures, though, were not measured the same way. In 1967 Mike Cotton of Motor Sport suggested that the Mk III's was a gross figure, and in January 1971 Boddy gave the Mk IV's as a net one, from an engine that was otherwise the Mk III's. The Triumph Sports Six Club puts it plainly:

The engine is often said to have been de-tuned from Mk3 spec, but in fact only the system of measuring output changed – from SAE to DIN – so the drop from 75bhp to 63bhp was not a real one. The MkIV was slower though, thanks to both extra weight and the taller gearing used to improve economy.

Triumph Sports Six Club, Mk IV model page

The later cars are less clear. triumphspitfire.com dates a milder camshaft to about FH25000, in 1972, and, by our arithmetic on Clive Richardson's figures for the 1500 in Motor Sport in 1975, the last Mk IVs were rated a little lower than Boddy's car.

The specification below gives the Mk IV's figures with their ratings, and the Mk III's are on its own page.⁠10​11​12​4​3​13​14​2

A purple Spitfire with its bonnet tipped forward, showing the engine, twin chrome air filters, coil spring and front wheel.
Under the tipped-forward bonnet of a purple Spitfire with the Mk IV's body, at the Haynes International Motor Museum, Sparkford, in June 2022; its chrome air filters are later additions.Andrew Bone, CC BY 2.0

Contents

How heavy is a Mk IV?

Fact check

779 kg

1,717 lb

Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26), model_ID=25, "Weight"⁠3

Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000, p. 83 spec table⁠15

Wikipedia (EN), "Triumph Spitfire", 2026, Mk IV section⁠11

734 kg

British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, Nov 1973 brochure, "Dimensions"⁠8

Our reading. The Triumph Sports Six Club calls its figure a kerb weight and Practical Classics prints the same, while British Leyland's French brochure of 1973 gives the lighter one as its poids à vide, an empty weight. None says what was in the car when it was weighed, so the sources read cannot settle the difference, and both stand.⁠3​15​8

Contents

How to spot a Mk IV

A Mk IV shares its body with the 1500, so check the details as well as the shape.

  1. The tail

    Cut off short, with a bumper that wraps round its corners.

  2. The bonnet

    Smooth along the tops of the wings (fenders): triumphspitfire.com's log says the raised edge and its finishing strip went with the Mk III.

  3. The doors

    Handles set into the door skins.

  4. The wheels

    Black centres on the steel wheels; the 1500's are silver.

  5. The dashboard

    Instruments in front of the driver, in a matt-black panel on the early cars and wood veneer from 1973.

  6. The nose

    A spoiler under the front bumper on the last Mk IVs, of 1974, as on the 1500.

  7. No 1500 transfers

    No "Spitfire 1500" on the bonnet or boot (trunk) lid.

  8. The numbers

    Outside North America a commission number from FH3 to FH64995, and an engine number beginning FH; identification reads both.⁠4​3​8​13​16​17​18​14​6

A red Spitfire in the Mk IV body with its black hood up, seen from behind on a wet street between parked cars.
A Spitfire in the Mk IV body seen from behind on a wet street in January 2015: the short tail, and a bumper that wraps round its corners, as on the 1500.Charlie from United Kingdom, CC BY 2.0
A chrome Spitfire IV badge on the red bonnet of a Spitfire, beside the headlamp and above the bumper.
A 'Spitfire IV' badge beside the headlamp of a red Mk IV at Vallet, France, in July 2026.Llann Wé², CC BY-SA 4.0

Contents

Changes, 1970–74

Triumph kept changing the Mk IV through its life. Most of the change points come from triumphspitfire.com's logs, which give no sources, so the table names who records each one.⁠14​8​13​7​16

FromChangeRecorded by
About FH25000, 1972A milder camshafttriumphspitfire.com
About FH28430A smaller fuel tanktriumphspitfire.com, though the tank in the November 1973 French brochure is still the bigger one
1973The wood dashboard with green lightingThe French brochure of 1973; triumphspitfire.com dates it to February, from about FH50000
1973Longer drive shafts and rear spring, so a wider rear trackMotor Sport, March 1975
1973Reclining seatstriumphspitfire.com
1974A spoiler under the front bumperMotor Sport, March 1975
January 1974A tonneau cover as standard in Britaintriumphspitfire.com; it is an option in the American brochure for the 1974 model year, probably a market difference
About FH60000A front chassis changed for impact rules, and the J-type overdrivetriumphspitfire.com; Canley Classics for the overdrive
A Spitfire Mk IV cockpit from above, with a black fascia, instruments ahead of the driver and black seats.
An early Mk IV's black dashboard, with the instruments facing the driver, in September 2012; the leather-rimmed wheel was fitted later.Akela NDE, CC BY-SA 2.0 fr
A red Spitfire cockpit from above, with a wood fascia, instruments ahead of the driver and black seats with headrests.
A wood dashboard of the kind fitted from 1973, in a red Spitfire with the Mk IV's body, photographed in September 2012.Akela NDE, CC BY-SA 2.0 fr

Contents

Production, price and options

The sources agree on how many Mk IVs were built: Canley Classics, Classic & Sports Car and the Triumph Sports Six Club are among the sources that print one figure, and the production table below gives it. None of them says whether it counts the American cars of the 1973 and 1974 model years, which had this body but were sold as Spitfire 1500s.

Boddy's test gave the price of the basic car in January 1971, purchase tax included, and the specification shows it beside the club's figure. His list of extras shows what a buyer could add: overdrive on third and top, switched from the gear-lever knob; a hardtop; wire wheels; radial or whitewall tyres; a tonneau cover; a radio; and a laminated windscreen (windshield). The hardtop and the other options are on hardtops and options.⁠1​3​10​4​17

A red Spitfire with a matching hardtop and wire wheels, parked in front of lock-up garages.
A hardtop and wire wheels on a red Spitfire that its photographer describes as a Mk IV, beside lock-up garages in January 2010.Jonnyk5614, CC BY 3.0

Contents

The American Mk IV

The Mk IV was also the American car of the 1971 and 1972 model years, and the Vintage Triumph Register's notes for those model years record the swing spring and the larger anti-roll bar. They were built with emission controls, and triumphspitfire.com gives them a single carburettor and a commission prefix of their own, FK. Classic & Sports Car gives them much less power than the British car, and Moss Motors and triumphspitfire.com give them different compression ratios; the American car's specification below shows the readings.

From the 1973 model year American cars kept this body but were given the 1500's longer-stroke engine ahead of everyone else, and the name Spitfire 1500 with it; cars for every other market waited for that engine until late 1974. North American Spitfires tells the American cars' story model year by model year.⁠17​14​2​19​16​1

Contents

On the road

Boddy's test car was red, with overdrive, a radio and radial tyres, and he "genuinely liked" it. He found the imitation-leather trim and moulded carpets good, the steering taut and smooth, and the grip on Dunlop's radials sure even in the wet. On bad surfaces the car shook and juddered a little. The engine ran smoothly above 2,000 rpm but grew busy near the top of third gear, the gear change was notchy, reverse was engaged by pressing the knob down, which he found a little unusual, and the brakes worked well if pushed firmly; as in 1963, there was no oil-pressure gauge. On performance he passed on a claim:

Weight is up by 54 lb. but performance is claimed not to have deteriorated, as improved manifolding has moderately uprated the power output.

Bill Boddy, Motor Sport, January 1971

What the other period testers found, and how they timed it, is on road tests.

Michelotti's body outlived the car it was drawn for. The 1500 kept it from late 1974 (from the 1973 model year in America), and the last Spitfire of all was built in it in August 1980.⁠4​20​1​21

A red open Spitfire turning at a seafront road junction, with the bay and town behind.
A red Spitfire, which its photographer names as a Mk IV, driven across a junction on Weymouth seafront, Dorset, in April 2021.Andrew Bone, CC BY 2.0

Contents

Specification: Mk IV

Production

Sources for Production, Mk IV

Price new
Several figures in print.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14
Price new£961 17s 6d

Price new, Mk IV

Several figures in print.

  • £961 17s 6dOne good source: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, incl. purchase tax, basic model, Jan 1971⁠4
  • £985One good source: Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26), "cost when new" (tax-paid)⁠3
  • £735Not yet confirmed: triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023, basic, before purchase tax⁠14

Engine

Sources for Engine, Mk IV

Capacity
Good sources agree.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; Canley Classics, "Engine Number Identification Chart"⁠18; Triumph Spitfire Club (Netherlands), "Spitfire modellen", "Aankoop informatie", "Clubinfo", home⁠22
Bore × stroke
Good sources agree.Three main bearings. Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8
Compression ratio
Good sources agree.97-octane fuel. Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14
Carburettors
One good source.Non-US. Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4
Capacity1,296 cc
Bore × stroke73.7 × 76 mm
Compression ratio9:1
Carburettorstwin SU HS2

Performance

Sources for Performance, Mk IV

Power
Several figures in print.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15; Wikipedia (DE), "Triumph Spitfire", 2026⁠23; Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975⁠13
Torque
Several figures in print.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15; Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975⁠13
Top speed
Several figures in print.British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975⁠13; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; triumphspitfire.com, "Top Speed and Track Test Results", 2023⁠24
0–60 mph
Several figures in print.Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15; Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975⁠13; triumphspitfire.com, "Top Speed and Track Test Results", 2023⁠24; Wikipedia (EN), "Triumph Spitfire", 2026⁠11
Power63 bhp

Power, Mk IV

Several figures in print.

  • 63 bhpGood sources agree: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, net, at 6,000 rpm; UK 1970–71⁠4; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000, net/DIN, at 6,000 rpm⁠15
  • 63 cvGood sources agree: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, at 6,000 rpm⁠8; Wikipedia (DE), "Triumph Spitfire", 2026, at 6,000 rpm⁠23
  • 61 bhpNot yet confirmed: Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975, about 61 bhp DIN for late Mk IVs, implied by the 1500's "increased by 10 b.h.p. DIN to 71" (our inference)⁠13
Torque837 lb in

Torque, Mk IV

Several figures in print.

  • 837 lb inOne good source: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, about 70 lb ft, at 3,500 rpm⁠4
  • 69 lb ftOne good source: Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000, at 3,500 rpm⁠15
  • 68 lb ftOne good source: Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975, at 2,900 rpm, late Mk IV⁠13
Top speed156 km/h

Top speed, Mk IV

Several figures in print.

  • 156 km/hOne good source: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, factory figure⁠8
  • rather less than 100 mphOne good source: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4
  • 92 or 95 mphNot yet confirmed: Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975, BL claim as reported; ambiguous⁠13
  • 90 mphOne good source: Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3
  • 90 / 87 mphNot yet confirmed: triumphspitfire.com, "Top Speed and Track Test Results", 2023, Autocar, in 4th / in overdrive⁠24
0–60 mph16.2 s

0–60 mph, Mk IV

Several figures in print.

  • 16.2 sGood sources agree: Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15
  • 12.5 sNot yet confirmed: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, "in standard trim"; not a measured result⁠4
  • 14.5 sOne good source: Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975, BL figure⁠13
  • 16.3 sNot yet confirmed: triumphspitfire.com, "Top Speed and Track Test Results", 2023, Autocar⁠24
  • 15.8 sNot yet confirmed: Wikipedia (EN), "Triumph Spitfire", 2026, citing Robson⁠11

Running gear

Sources for Running gear, Mk IV

Steering
One good source.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4
Overdrive
One good source.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4
Front brakes
Several figures in print.British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19⁠25
Rear brakes
Several figures in print.British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19⁠25
Tyres
Several figures in print.Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14; British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8
Wheels
Several figures in print.British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19⁠25; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15
Steering3.7 turns lock to lock, 15 in three-spoke wheel
Overdriveon 3rd (4.34:1 overall) and top (3.12:1 overall), D-type, optional
Front brakes228 mm (9 in) discs

Front brakes, Mk IV

Several figures in print.

  • 228 mm (9 in) discsGood sources agree: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8
  • 9 in (229 mm) discsGood sources agree: Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19, all models⁠25
Rear brakes7 × 1¼ in (178 × 32 mm) drums

Rear brakes, Mk IV

Several figures in print.

  • 7 × 1¼ in (178 × 32 mm) drumsGood sources agree: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8
  • 7 in (178 mm) drumsGood sources agree: Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19, all models⁠25
Tyres5.20-13 cross-ply standard; Dunlop SP68 radials optional

Tyres, Mk IV

Several figures in print.

  • 5.20-13 cross-ply standard; Dunlop SP68 radials optionalOne good source: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, 1971⁠4
  • 5.20-13 cross-ply standard; radials optionalNot yet confirmed: triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023, 1971⁠14
  • 145 SR 13 radialOne good source: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, France 1973 (standard by then)⁠8
Wheels13 × 4½ J

Wheels, Mk IV

Several figures in print.

  • 13 × 4½ JOne good source: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15
  • 13 × 4½ J wire wheelsOne good source: Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19, wire wheels (option), Mk I–IV⁠25

Dimensions and weight

Sources for Dimensions and weight, Mk IV

Length
Good sources agree.Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8
Width
Good sources agree.58.5 in. British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3
Height
Several figures in print.British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3
Kerb weight
Good sources disagree.Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000⁠15; British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Wikipedia (EN), "Triumph Spitfire", 2026⁠11
Wheelbase
Good sources agree.83 in. British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3
Ground clearance
Good sources agree.Laden; 5 in. British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4
Fuel tank
Several figures in print.British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919⁠8; Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971⁠4; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14
Length3,786 mm
Width1,488 mm
Height1,205 mm

Height, Mk IV

Several figures in print.

  • 1,205 mmOne good source: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, hood up⁠8
  • 1,125 mmGood sources agree: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, to the top of the windscreen⁠8; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26), to the top of the windscreen⁠3
Kerb weight779 kg

Kerb weight, Mk IV

Good sources disagree.

  • 779 kgDisputed: Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000, 779 kg⁠15; Wikipedia (EN), "Triumph Spitfire", 2026, citing Robson⁠11
  • 734 kgDisputed: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, unladen⁠8
Wheelbase2,110 mm
Ground clearance127 mm
Fuel tank37.6 L

Fuel tank, Mk IV

Several figures in print.

  • 37.6 LOne good source: British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, France, Nov 1973⁠8
  • 8.5 galOne good source: Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, Imperial (38.6 L), Jan 1971 test car⁠4
  • 8.25 → 7.25 galNot yet confirmed: triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023, imperial gallons; cut from FH28430 (contradicted by the 1973 French brochure)⁠14

Contents

Specification: US

Engine

Sources for Engine, US

Compression ratio
Several figures in print.Moss Motors, "Car Specifications – Triumph Spitfire Mk IV 1971–1974"; "…Spitfire 1500 (1975–1980)"⁠19; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14
Compression ratio8.5:1

Compression ratio, US

Several figures in print.

  • 8.5:1Not yet confirmed: Moss Motors, "Car Specifications – Triumph Spitfire Mk IV 1971–1974"; "…Spitfire 1500 (1975–1980)", US 1971–72⁠19
  • 8.0:1Not yet confirmed: triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023, US 1972, FK engines⁠14

Performance

Sources for Performance, US

Power
Several figures in print.Malcolm McKay, "Triumph Spitfire buyer's guide: what to pay and what to look for", Classic & Sports Car, 10 May 2019⁠2; Hagerty (US), Valuation and model overview pages (US)⁠26
Top speed
Not yet confirmed.US 1971. triumphspitfire.com, "Top Speed and Track Test Results", 2023⁠24
0–60 mph
Not yet confirmed.Road & Track, May 1971 (US car). triumphspitfire.com, "Top Speed and Track Test Results", 2023⁠24
Power48 bhp

Power, US

Several figures in print.

  • 48 bhpOne good source: Malcolm McKay, "Triumph Spitfire buyer's guide: what to pay and what to look for", Classic & Sports Car, 10 May 2019, US Mk IV 1300; rating not stated⁠2
  • 58 bhpNot yet confirmed: Hagerty (US), Valuation and model overview pages (US), US 1971–72, at 5,200 rpm⁠26
Top speed86 mph
0–60 mph15.9 s

Dimensions and weight

Sources for Dimensions and weight, US

Length
One good source.US Mk IV 1971–74 (one figure for the whole span, so not written to the 1971–72 node's specs). Moss Motors, "Car Specifications – Triumph Spitfire Mk IV 1971–1974"; "…Spitfire 1500 (1975–1980)"⁠19
Kerb weight
One good source.Kerb, US Mk IV and 1500 (unladen 1,638–1,761 lb). Moss Motors, "Car Specifications – Triumph Spitfire Mk IV 1971–1974"; "…Spitfire 1500 (1975–1980)"⁠19
Length155.25 in
Kerb weight1,750–1,850 lb

Contents

Production

Production: how far the sources agree

70,021, Mk IV, Nov 1970–Dec 1974; whether the US 1973–74 FM cars are included is not stated
Good sources agree.

  1. 70,021Mk IV, Nov 1970–Dec 1974; whether the US 1973–74 FM cars are included is not stated

    Canley Classics, "Production Figures"⁠1; Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26)⁠3; Classic & Sports Car, A–Z of classics: Triumph Spitfire I, II, III, MkIV, 1500⁠10; Wikipedia (EN), "Triumph Spitfire", 2026⁠11; Triumph Spitfire Club (Netherlands), "Spitfire modellen", "Aankoop informatie", "Clubinfo", home⁠22; triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023⁠14

Contents

Sources

Sources are given as plain text; their addresses are on the sources page.

  • Primarymade at the time, by the maker or by people who were there
  • Referenceserious later work: clubs, specialists, magazines, books
  • Uncheckedencyclopaedias and enthusiast sites: cited beside a good source, named in the sentence, or marked Unchecked
  1. Canley Classics, "Production Figures", Spitfire MK IV, November 1970–December 1974; Spitfire MK IV row; Spitfire 1500 row; Spitfire 1500, December 1974–August 1980; Production Figures table, row "Spitfire MK IV". Reference
  2. Malcolm McKay, "Triumph Spitfire buyer's guide: what to pay and what to look for", Classic & Sports Car, 10 May 2019, timeline, October 1970; US section. Reference
  3. Triumph Sports Six Club, Model pages: Spitfire 4/Mark II (model_ID=24), Mark III (23), Mark IV (25), 1500 (26), Mark IV page; model_ID=25, "Weight"; Mark IV page, "Weight"; Mark IV and 1500 pages, wheel centres; Mark IV page, quantity and cost when new; model_ID=25 (Mark IV page), "Cost when new"; model_ID=25 (Mark IV page) ("SAE to DIN"); model_ID=25 (Mark IV page); model_ID=25, "Dimensions"; model_ID=25, "Quantity". Reference
  4. Bill Boddy ("W.B."), "Road test: The Triumph Spitfire Mk. IV", Motor Sport, Jan 1971, p. 59; p. 59: body, facia, gearbox, axle ratio, equipment; p. 59: anti-roll bar; the Silverstone impressions of November 1970; p. 59, the engine; p. 59: body, wheels, facia; p. 59, final paragraph: price and extras; Jan 1971 p. 59, final paragraph; Jan 1971 p. 59, engine paragraph; Jan 1971 p. 59, consumption paragraph; Jan 1971 p. 59, controls paragraph; Jan 1971 p. 59, engine paragraph ("63 (net) b.h.p."); Jan 1971 p. 59. Primary
  5. Graham Robson, "Harry Webster – My Technical Mentor", Moss Motoring (Moss Motors), 12 Jun 2019, Michelotti and the prototype. Reference
  6. BL Cars / Jaguar Rover Triumph Ltd, Triumph Spitfire 1500 (sales brochure), UK, 12/1978, Publication No. 3254/D, description of the body: wrap-round bumpers. Primary
  7. John Kipping (overdrive articles), Technical articles (group): "Swing Springs", "Rear End Noises", "Propshaft Problems", "Oil Consumption", "Unleaded Engines", "The D-Type Overdrive", "The J-Type Overdrive", "Different Differentials", "Close Ratio Gearboxes For Spitfire MkIV/1500", "Chrome Bumpers", "Spitfire Tuning Kits", "Fitting Le Mans Style Bonnet Vents", Canley Classics, "Swing Springs"; "The J-Type Overdrive". Reference
  8. British Leyland (France), Triumph Spitfire Mk4 (sales brochure), France, 11/1973, T.919, description: the wood dashboard; Nov 1973 brochure, "Dimensions"; "Dimensions", poids à vide; description: dashboard and rear track; "Capacités"; Nov 1973 brochure, "Moteur"; Nov 1973 brochure, "Performances"; Nov 1973 brochure, "Freins"; Nov 1973 brochure, "Pneus"; Nov 1973 brochure, "Roues"; Nov 1973 brochure, diagram "B"; Nov 1973 brochure, diagram; Nov 1973 brochure, diagram "A"; Nov 1973 brochure, "Empattement"; Nov 1973 brochure, "Capacités". Primary
  9. Sam Skelton, "Buying Guide: Triumph Spitfire (1962–1980)", Hagerty UK, 3 Feb 2021, handling. Reference
  10. Classic & Sports Car, A–Z of classics: Triumph Spitfire I, II, III, MkIV, 1500, Triumph Spitfire MkIV; A–Z entry. Reference
  11. Wikipedia (EN), "Triumph Spitfire", 2026, Mk IV section; production figures, citing Robson 1982 p. 187. Unchecked
  12. Mike Cotton ("M.L.C."), "Triumph Spitfire to Monaco", Motor Sport, Jun 1967, p. 26, the engine. Primary
  13. Clive Richardson ("C.R."), "Road Impressions – The Triumph Spitfire 1500", Motor Sport, Mar 1975, p. 25, the power output; p. 25: transfers and the front spoiler; p. 25: the rear track and the front spoiler; Mar 1975 p. 25, text; Mar 1975 p. 25, para 4. Primary
  14. triumphspitfire.com ("Spitfire & GT6 Magazine and Information Warehouse"), Reference pages (group): models and options; Mk I–1500 options-and-changes logs; engine numbers; 1979–80 VINs; what year is my car; final drive; general specification data; stock tyres; wheel alignment; lubrication; tuning; fuses; paint and trim codes; side stripes; decal and badge placements; wire wheels; head swaps; substitute parts; suppliers; new owner; pre-purchase checklist; spotters guide, pages modified 2023, Mk IV options-and-changes log, FH25000; Mk IV options-and-changes log, body; Mk IV options-and-changes log; models page; engine numbers; Mk IV page, basic price; engine page; stock tyre page; Mk IV change log; Mk IV table; models page. Unchecked
  15. Practical Classics, "Buyers Guide: Triumph Spitfire", May 2000, p. 83 spec table; p. 83, specification table. Reference
  16. British Leyland Motors Inc., Spitfire 1500 (sales brochure), USA, 1974 model year, SP741, 1973, "New for 1974", the spoiler; options: tonneau cover; cover. Primary
  17. Vintage Triumph Register, "Spitfire" (production history, production dates and numbers, buyer's guide tabs), production dates and numbers: FH3–FH64995; production dates and numbers: 1973–1974; production dates and numbers: 1971–1972 and 1973–1974. Reference
  18. Canley Classics, "Engine Number Identification Chart", FH; engine chart, prefix FH. Reference
  19. Moss Motors, "Car Specifications – Triumph Spitfire Mk IV 1971–1974"; "…Spitfire 1500 (1975–1980)", Spitfire Mk IV 1971–1974, compression ratio; Mk IV spec page; Mk IV and 1500 spec pages. Reference
  20. Bill Boddy ("W.B."), "Sports cars under £700: the £641 Triumph Spitfire 4", with data panel "The Triumph Spitfire 4", Motor Sport, Apr 1963, the missing oil-pressure gauge. Primary
  21. British Motor Museum, "Spitfire 1500 (last of line), 1980", accession 1980-1-190, object record. Primary
  22. Triumph Spitfire Club (Netherlands), "Spitfire modellen", "Aankoop informatie", "Clubinfo", home, engine-number table, prefix FH; "Spitfire modellen" page, production figures. Reference
  23. Wikipedia (DE), "Triumph Spitfire", 2026, Datenblatt. Unchecked
  24. triumphspitfire.com, "Top Speed and Track Test Results", 2023, test-results table. Unchecked
  25. Triumph Sportscars (Australia; closed end of 2016), "Spitty Tips" 2, 3, 4, 5, 6, 8, 19, Spitty Tips, brakes; Spitty Tips 5. Reference
  26. Hagerty (US), Valuation and model overview pages (US), search snippet (page not read). Unchecked

Contents