Triumph Stag buyer's guide

The Triumph Stag is a four-seat 2+2 convertible grand tourer with Triumph's own 3.0-litre V8, styled by Giovanni Michelotti and built from 1970 to 1977. It has a T-bar roll-over structure, a soft top and a removable hardtop, with power steering and electric windows as standard.

People buy a Stag for the V8 sound, open-air touring with room for four, and strong club and specialist support. Its 1970s reputation for overheating still follows it. A well-maintained car is a usable classic; a neglected one can be very costly.

This is a short buying and selling summary for anyone looking at a Stag at a dealer, privately or at an auction such as Mathewsons in North Yorkshire. For the full history, production data and a detailed buying guide, see the Triumph Stag archive.

By Jon Cosson · Checked 20 October 2026

At a glance

Built	1970 to 1977 (launched June 1970)
Total made	Approximately 25,939 (17,819 UK market, 8,120 export)
Survivors	8,369 recorded as active on DVLA records, licensed or SORN (Q3 2023)
Body	Four-seat 2+2 convertible, T-bar roll-over structure, soft top and removable hardtop
Engine	Triumph 2,997 cc V8, single overhead camshaft per bank, twin Zenith-Stromberg carburettors
Power	145 bhp net at 5,500 rpm (period UK specification)
Gearbox	Four-speed manual with optional Laycock overdrive, or Borg-Warner three-speed automatic
Factories	Bodies built, painted and trimmed at Triumph's No. 2 plant, Speke; final assembly at Canley, Coventry
Styling	Giovanni Michelotti, based on a shortened Triumph 2000 floorpan
Typical uses	Touring, club runs, shows, summer road use
Main club	Stag Owners Club

The Triumph Stag in brief

The Stag began in 1965, when Michelotti asked Triumph's Director of Engineering, Harry Webster, for a Triumph 2000 saloon to turn into a show car. Webster agreed on condition that Triumph had first refusal. The result, a convertible on a shortened 2000 floorpan, was taken to Coventry in 1966 for production development, and Stag, the development code name, stayed for the showroom.

The engine was originally planned as a 2.5-litre V8. The change to 3.0 litres in 1968 was proposed under Harry Webster and taken over by Spen King, and was achieved by increasing the bore. Mechanical fuel injection was dropped in favour of twin Zenith-Stromberg carburettors, largely to meet planned US emission rules. Every factory Stag left Triumph with carburettors.

Every production body was built, painted and trimmed at Triumph's No. 2 plant at Speke in Liverpool, then taken to Canley in Coventry for final assembly. The car was launched in June 1970 as a luxury convertible priced below rivals such as the Mercedes-Benz SL.

The Stag was partly aimed at America, where Triumph hoped for strong sales. America rejected it on price, market positioning and, ultimately, its reliability reputation, and it was withdrawn from the US after only a few years. Total production of approximately 25,939 fell well short of the original sales plan, and the car ended in 1977 with no direct successor.

Mk1 and Mk2 are enthusiast terms coined after production ended, not factory names, and the differences are mainly trim and cosmetic. For a buyer, the engine, cooling system and structure matter far more than the version.

Versions to know

Version	Years	What to know
Mk1 (enthusiast term)	1970 to 1973	Early cars with no coach lines, stripes or black panels. Early steel is often said to have resisted rust better, though condition now depends on past care.
Mk2 (enthusiast term)	1973 to 1977	Mainly trim and cosmetic changes: twin coach lines, black sills and rear panel, and clearer gauges. Alloy wheels were optional, then standard from late 1975, when the rear panel became body colour.
Manual	Throughout production	Four-speed gearbox, usually with Laycock overdrive. The enthusiast choice, and more common among UK survivors than the automatic.
Automatic	Throughout production	Borg-Warner three-speed with no overdrive, so it revs higher on the motorway. Suits the car's relaxed touring character.
Engine conversions	Various	Many cars have been fitted with a Rover V8, Ford Essex V6 or other engine. Good ones can be usable cars, but they are not original and appeal less at the top of the market.

Pros and cons

Pros	Cons
A four-seat convertible with a V8, a rare combination among British classics. Relaxed grand touring manners, with power steering as standard. Strong club support and a large specialist network. Mechanical and cooling parts are well supported. Engine problems are well understood and can be cured by competent work.	A neglected V8 can need a very costly rebuild. Cooling was marginal from new and punishes poor maintenance. Rust in the A-posts, sills and scuttle is serious and expensive. Trim and some body panels are harder to find than mechanical parts. Many cars have been converted or poorly restored, so originality needs checking.

Myths and realities

Every Stag engine is a time bomb.

The reputation comes from the 1970s. A correctly sorted V8 with a healthy cooling system and regular timing chain changes can cover high mileages. History matters more than the badge.

The V8 is two Dolomite engines joined together.

This is loose shorthand. The V8 and the slant-four were designed as a related family, and the four was the parent design.

Mk1 and Mk2 are official Triumph models.

Triumph never used these terms. Enthusiasts coined them after production ended, and the differences are mainly trim and cosmetic.

What to check

Bodywork and structure

Bring a torch and a magnet, and work from front to back. Later cars are often said to rust worse, and fresh underseal is a reason to look harder.

A-posts, including behind the carpet trim: rot here affects the T-bar structure and door fit, and often means the rest of the car is rotten.
Sills: look for waves, filler and cover sills welded over old metal. Do not confuse these with the stainless decorative oversills.
Scuttle: rot traps water and repair means removing the screen and dash.
Inner and outer wings, especially the inner wing top seams and arches.
Floors under the carpets, the boot floor and spare wheel well.
Front valance, behind the headlights and the battery tray.
Where the T-bar and roll hoop meet the body.

Engine

Insist on a completely cold start. The exhaust manifolds and top hose should be cold when you arrive, because a warm engine can hide hard starting, smoke or overheating.

Idle for at least 15 minutes. The gauge should rise, settle and hold. Be wary if the seller wants to stop early.
Once warm, both radiator hoses should be hot. A cool bottom hose suggests a clogging radiator.
Continuous bubbling in the expansion tank points to a head gasket problem; treat it as a reason to walk away.
A metallic rattle at the front that persists when warm means the timing chains are due. The engine is an interference design.
Mayonnaise-like residue under the filler cap or on the dipstick suggests coolant and oil mixing.
The oil pressure light should come on with the ignition and go out within a second or two of starting.
Ask for receipts for cooling system, head and timing chain work, and for regular antifreeze changes.

Gearbox and drivetrain

Confirm which gearbox is fitted before the test drive.

Overdrive should engage cleanly and drop the revs. Faults are often the switch, relay or solenoid, but can be the unit.
Manual: a whine that quietens when the clutch is dipped points to a worn layshaft bearing. Check for weak synchromesh.
Automatic: check fluid level and colour, and for clean shifts and a working kickdown.
A rear-end lurch on and off the throttle usually means dry driveshaft splines.
Listen for rumble or whine from the rear axle.

Suspension, steering and brakes

The Stag is a tourer, not a sports car, but it should feel tidy and stable.

Wayward rear handling suggests worn trailing arm bushes; probe the mountings for rust.
Soggy handling may mean tired dampers, springs or bushes.
Check the power steering for leaks. Over-light, vague steering can point to a faulty rack valve.
Check tyre date codes; tyres over about ten years old, or with sidewall cracking, need replacing.

Electrics and instruments

The Lucas wiring is conventional and most faults come from age and poor earths.

Test every light, the wipers, horn, switches and heater.
Intermittent rear lights often mean a corroded bulb holder or earth.
Electric windows: slow operation is usually tired motors or runners, but check the wiring.
The factory temperature sender reads one cylinder head only, so many owners add a second sender or gauge.

Interior, hood and hardtop

Roof parts are easy to overlook and costly to put right.

Confirm a working soft top is in the well, and check the frame, fabric, catches and seals.
Ask for the hardtop to be removed, or shown to be removable, and check its edges for rust.
Check the seats, carpets and trim; some trim parts are harder to find.

Paperwork and originality

Documentation is what separates a sorted Stag from a gamble.

Check the V5C against the commission plate and engine number.
An original engine has twin Zenith-Stromberg carburettors, alloy heads and a cross-over inlet manifold.
Any engine transplant should be documented, with proper cooling, mounts and wiring.
Treat a restored car with no invoices or photographs with suspicion.
The Stag Owners Club can help confirm a car's original details.

On the test drive

Start the engine from cold yourself.
Drive long enough to get it fully hot, then let it idle and watch the gauge.
Check overdrive engagement or automatic shifts under load.
Feel for a rear-end twitch on and off the throttle.
Raise the hood or fit the hardtop to check the seals.
Afterwards, check for coolant loss and for oil and water mixing.

Buying at auction

Stags appear regularly at UK auctions, including Mathewsons in North Yorkshire. Because the key checks involve a cold start and a long warm-up, an auction car carries more unknowns than one bought privately.

What you can check in viewing week

Use a torch underneath on the sills, floors, A-posts and boot floor.
Use a magnet on the sills, wings and lower panels for filler.
Check the commission plate and engine number against the V5C.
Check oil, coolant and the filler cap for contamination.
Hear it start if allowed, ideally from cold.

What you usually cannot do

You usually cannot drive it, so gearbox, overdrive and axle faults stay hidden.
You cannot run a long warm-up to test the cooling.
You usually cannot put it on a lift.

Tips

Read the catalogue critically; words like sorted or restored need invoices behind them.
Look for cooling, head and timing chain receipts in the history file.
Remember the buyer's premium is added to the hammer price.
Set your limit before the sale and stick to it.
Arrange transport home in advance.

What makes one more desirable

The original Triumph V8, in good health, with documented history.
Sound structure, especially A-posts, sills and scuttle.
Manual with overdrive is the enthusiast favourite, though good automatics have a following.
A complete car with a good soft top and its hardtop.
Factory colours; black or silver cars are usually repaints.

This guide does not give values or predict prices.

Selling a Triumph Stag

Stag buyers know the weak points, so evidence sells a car. Be ready to show that the engine and cooling have been looked after.

Preparing the car

Fix small faults such as warning lights, window motors and hood catches.
Let buyers do a cold start.
Clean underneath so the structure can be seen.
Present both tops in good order.

Paperwork

V5C, MOT history and every invoice, in date order.
Receipts for cooling, head and timing chain work.
Restoration photographs and any conversion details.

Where to sell

Stag Owners Club adverts.
Specialist classic car websites and magazines.
Auctions such as Mathewsons, where good photographs and a clear description help.

Writing the description

State the gearbox and whether the engine is original.
Describe any conversion honestly.
List known faults; buyers will find them anyway.

Living with one

Mechanical and cooling parts are well supported; trim and some panels are harder to find.
Keep the cooling system flushed with inhibited antifreeze and treat timing chains as a service item.
Uprated radiators, electric fans and an extra temperature sender are common upgrades.
Vehicles over 40 years old can apply for historic vehicle tax and MOT exemption, though a regular check is still sensible.
Classic insurance is usually agreed value with limited mileage.

Clubs and registers

Stag Owners Club

Questions people ask

Is the Triumph Stag reliable?

It can be. Most problems come from overheating, so a car with a well-maintained cooling system, regular antifreeze changes and recent timing chains is far more dependable than its 1970s reputation suggests.

What should I look for when buying a Stag?

A full cold start and long warm-up, evidence of cooling and timing chain work, and a sound structure, especially the A-posts, sills and scuttle. Check the hood and hardtop too.

How many Triumph Stags were made?

Approximately 25,939 were built from 1970 to 1977: 17,819 for the UK market and 8,120 for export.

How many Stags survive in the UK?

DVLA data for Q3 2023 recorded 8,369 Stags as active, either licensed or on SORN.

What is the difference between a Mk1 and Mk2 Stag?

These are enthusiast terms, not Triumph ones. The differences are mainly trim and cosmetic, such as coach lines, panel colours and gauges, rather than mechanical.

Should I buy a manual or automatic Stag?

Manual cars with overdrive are the enthusiast choice and the more common survivor. The automatic suits relaxed touring but has no overdrive. Condition matters more than gearbox.

Why did the Stag fail in America?

America rejected it on price, market positioning and, ultimately, its reliability reputation, and it was withdrawn after a few years.

Sources

Checked 20 October 2026.

An independent guide. Not a valuation and not financial advice. Always inspect a car in person or have it inspected before you buy.