Triumph TR6 buyer's guide

The Triumph TR6 was the last of the separate-chassis TR sports cars. It took the TR5's 2.5-litre straight-six, chassis and independent rear suspension and wrapped them in a squarer body restyled by Karmann of Germany. Home-market cars used Lucas mechanical petrol injection, while the far larger number built for North America used twin Stromberg carburettors.

People buy a TR6 for the sound and pull of the six, an open-top driving experience that feels firmly old school, and very strong club and specialist support. The catch is that most cars are now well over 45 years old, many have been restored at least once, and the quality of that work varies enormously.

This guide is for anyone looking at a TR6 at a dealer, privately or at an auction such as Mathewsons in North Yorkshire. It covers the versions, the areas that matter most, how to tell a genuine UK fuel-injected car from a converted US import, and how to sell one well.

By Jon Cosson · Checked 20 October 2026

At a glance

Built	1968 to 1976 (launched January 1969)
Total made	91,850
Fuel-injected (PI) cars	13,703, built November 1968 to February 1975
Carburettor cars	Around 78,000, almost all for export, mainly North America
Body	Two-seat roadster on a separate chassis; factory hardtop optional
Engine	2,498cc straight-six, overhead valves
Power	150bhp (CP), 125bhp (CR), about 104bhp US carburettor cars
Gearbox	Four-speed manual, optional overdrive, standard on later cars
Suspension	Front double wishbones; independent semi-trailing arm rear with lever-arm dampers
Body restyle	Karmann, based on the TR5 centre section
Typical uses	Summer touring, club runs, shows, light road use
Main club	TR Register

The Triumph TR6 in brief

The TR6 was a quick and economical way for Triumph to modernise the TR5. Karmann redesigned the front and rear while keeping the centre section of the body, giving the car its squared-off nose and cut-off tail. Underneath, the chassis, engine and semi-trailing arm rear suspension carried over, along with rack and pinion steering and wider wheels than before.

The engine is the key to the car. UK and some other market cars used Lucas mechanical fuel injection and were rated at 150bhp in early CP-series form. North American cars, which made up the large majority of production, used twin Stromberg carburettors and emissions equipment, and produced only a little over 100bhp.

The main change came for the 1973 model year, when the CR series replaced the CP. The injected engine was given a milder camshaft and was rated at 125bhp, although the TR Register notes that the figures were measured to different standards and the drop was less severe than it looks. The same update brought a front chin spoiler, a plastic scuttle vent grille and new instruments. The carburettor cars moved from the CC to the CF series at the same point.

Overdrive was an option for most of production and became standard from about the 1974 model year. Early cars used the Laycock A-type overdrive, which worked on second, third and top; later CR and CF cars switched to the J-type, and overdrive on second was dropped. Injected car production ended in February 1975 and the last carburettor cars were built in July 1976.

For a buyer today, the important point is that the TR6 market is a mix of original UK PI cars, US cars repatriated in the 1980s onwards, and US cars converted to right-hand drive and often to fuel injection. All three can be good cars, but they are not the same thing and should not be described as such.

Versions to know

Version	Years	What to know
TR6 PI (CP series)	1968 to 1972	Home-market and some export cars with Lucas mechanical fuel injection, rated at 150bhp. Commission numbers begin CP. Early cars used the A-type overdrive where fitted. These are the most sought-after cars.
TR6 PI (CR series)	1972 to 1975	Revised for the 1973 model year with a milder camshaft, rated at 125bhp. Chin spoiler, new instruments and the J-type overdrive, which became standard from around the 1974 model year. Commission numbers begin CR. Production ended in February 1975.
TR6 carburettor (CC series)	1968 to 1972	Built mainly for North America with twin Stromberg carburettors and emissions equipment, about 104bhp. Left-hand drive. Commission numbers begin CC.
TR6 carburettor (CF series)	1972 to 1976	Later US-market cars with the same broad updates as the CR, plus increasing emissions equipment. Commission numbers begin CF. Many have been imported to the UK.
Re-imports and conversions	Various	US cars brought to the UK, sometimes left as left-hand-drive carburettor cars, sometimes converted to right-hand drive, and sometimes fitted with fuel injection or other engine upgrades. Quality of conversion varies widely.
Factory hardtop	Throughout production	An optional one-piece hardtop was offered alongside wire wheels, overdrive and a tonneau cover. A genuine factory hardtop adds to the appeal of a car.

Pros and cons

Pros	Cons
Smooth, torquey 2.5-litre straight-six with a distinctive exhaust note Early PI cars are genuinely brisk, with 0 to 60mph quoted at a little over eight seconds Separate chassis makes major restoration and accident damage easier to assess Excellent club support from the TR Register and other Triumph clubs Most mechanical, trim and body parts are widely available, including new chassis Simple layout that a good specialist understands well Large numbers built, so there is plenty of choice Options such as overdrive, hardtop and wire wheels let you find a car to suit your use	Rust in the chassis and body is common and repairs are not cheap Rear trailing arm mounting points on the chassis are a well-known weak spot The Lucas fuel injection needs knowledgeable setting up and its original pump runs hot Crankshaft thrust washer wear can ruin an engine if ignored Driveshafts and differential mounts wear, causing clunks from the rear Many cars are US imports, so originality claims need checking Firm, old-fashioned ride and heavy controls by modern standards Variable restoration quality hidden under fresh paint

Pros

Cons

Smooth, torquey 2.5-litre straight-six with a distinctive exhaust note
Early PI cars are genuinely brisk, with 0 to 60mph quoted at a little over eight seconds
Separate chassis makes major restoration and accident damage easier to assess
Excellent club support from the TR Register and other Triumph clubs
Most mechanical, trim and body parts are widely available, including new chassis
Simple layout that a good specialist understands well
Large numbers built, so there is plenty of choice
Options such as overdrive, hardtop and wire wheels let you find a car to suit your use

Rust in the chassis and body is common and repairs are not cheap
Rear trailing arm mounting points on the chassis are a well-known weak spot
The Lucas fuel injection needs knowledgeable setting up and its original pump runs hot
Crankshaft thrust washer wear can ruin an engine if ignored
Driveshafts and differential mounts wear, causing clunks from the rear
Many cars are US imports, so originality claims need checking
Firm, old-fashioned ride and heavy controls by modern standards
Variable restoration quality hidden under fresh paint

Myths and realities

The 125bhp CR car is far slower than the 150bhp CP.

The figures were measured to different standards and the TR Register notes the detune was less severe than it appears. Condition and set-up matter more than series.

Fuel injection is too unreliable to live with.

The system had a poor reputation when new, but it is now well understood. Common upgrades include a more modern fuel pump, and a specialist can set the system up properly.

Any right-hand-drive TR6 with fuel injection is an original UK car.

Many US carburettor cars have been converted to right-hand drive and injection. The commission number prefix and factory records tell you what the car started as.

A fresh restoration means the chassis is sound.

Paint can hide rot and poor repairs. Ask for photographs of the work and look underneath for yourself.

What to check

Chassis

The chassis is made from pressed steel sections that trap moisture inside. Check it first, because it decides whether the car is a sound buy or a restoration.

Rear trailing arm mounting points on the chassis: a common MOT failure and potentially dangerous if weak. Look for swelling, flaking and fresh patches.
The chassis around the rear axle and differential: these sections can rot from the inside out, so swelling around bolts is an early warning.
The area ahead of the rear wheels where chassis members meet between bracing plates.
Differential mountings: the front mounts are prone to breaking or tearing away from the chassis.
Door gaps that open up at the top or close at the B-post, which suggest the chassis is sagging.
Kinks, ripples or crude welding that indicate past accident damage, which is easy to spot on a separate chassis.
Ask whether the car has had a replacement chassis or a body-off restoration and what records exist.

Bodywork

Rot-free original body panels are rare. Use a magnet and look closely at the known traps.

Front wings, particularly the top edges and around the headlamps.
Bonnet leading edge and the rear lip of the boot lid.
Rear wing to rear deck join, where several layers of metal trap road dirt.
Rear wings at the wheelarch lips, behind the rear wheels and at the lower edges.
Base of each B-post where it meets the sill, near the seatbelt mountings.
Sills, floorpans and the boot floor, including the spare wheel well.
Door bottoms and top edges near the seal.
Panel fit and paint finish: poor gaps and filler often point to hurried repairs.

Engine and fuel injection

The six is tough if maintained, with a life of around 100,000 miles or more between rebuilds. The two things to check are crankshaft end float and the state of the fuel system.

Crankshaft thrust washers: with the engine off, push and pull the front crankshaft pulley, then watch it while someone presses the clutch. Noticeable movement means worn or missing thrust washers, which can scrap the engine if left.
Oil pressure should be strong when warm. Low pressure, smoke and rough running are warning signs.
Oil leaks are normal to a degree; heavy leaks are not.
Start-up rattles are common but should fade quickly.
On PI cars, ask what has been done to the fuel pump. The original Lucas pump overheats and many have been replaced with a more modern unit.
Hard hot starting, misfires and black smoke under load point to fuel injection set-up or metering unit problems. A specialist can test the system.
Check for a service history from someone who knows these injection systems.
Look for coolant leaks and signs of overheating, and check the cooling fan works.

Gearbox, overdrive and rear axle

The drivetrain is robust but wears, and several noises are worth recognising.

Worn layshaft bearings cause a rumble in the intermediate gears that disappears in top.
Grinding when changing into any gear apart from top suggests synchromesh wear.
Check that overdrive engages and disengages promptly in each gear it is meant to work in.
Note which overdrive is fitted: A-type on earlier cars, J-type on later CR and CF cars. Swaps are common.
Clunks from the rear on take-off or when lifting off can come from worn driveshafts or failing differential mounts. Both sound similar.
Look for oil leaks from the differential.
A slipping or juddering clutch, and a release bearing that sounds rough when the pedal is pressed.

Suspension, steering and brakes

Independent suspension at both ends gives a good ride for the period, but bushes, dampers and steering joints all wear.

Rear lever-arm dampers: leaks and weak damping are common, and many cars have been converted to telescopic dampers.
Rear suspension bushes and the trailing arms themselves, looking for cracks and corrosion.
Play in the rear wheels and hubs when rocked, which a specialist can diagnose.
Front trunnions and wishbone bushes: these need regular lubrication, so ask about servicing.
Steering rack for play and leaks, and steering that pulls to one side.
Wire wheels for broken or loose spokes; bent wheels should be replaced, not ignored.
Brakes that pull, judder or feel spongy.

Electrics and instruments

The Lucas electrical system is simple, but age, poor earths and amateur additions cause most faults.

Test every light, indicator, wiper speed, horn and gauge.
Signs of rewiring, such as functions that interfere with each other, for example indicators that work only with the wipers on.
Look under the dashboard for a tangle of non-standard wiring and loose connectors.
Check the fusebox for corrosion.
Check the overdrive switch and the wiring to the overdrive solenoid.
Ensure the charging light goes out once the engine is running.

Interior and trim

Trim is widely available in original colours, so condition affects cost rather than whether a car can be saved.

Seats with split seams, torn covers or sagging foam.
Wooden dashboard and door cappings with cracked or peeling lacquer.
Hood condition, fit and the state of the frame and rear window.
Carpets and floors: lift them to check for damp and rust underneath.
Hardtop, if fitted: ask whether it is a factory item and check its seals.
Non-original seats or steering wheels, which may matter to buyers seeking originality.

Paperwork and originality

Knowing what a TR6 started life as is central to judging it.

Check the commission number on the car against the V5C. CP and CR prefixes indicate a factory fuel-injected car; CC and CF indicate a carburettor car, usually built for the US.
A right-hand-drive fuel-injected car with a CC or CF commission number has been converted. That is not a problem in itself, but it must be described honestly.
Check the engine number and ask whether it is the original engine.
A British Motor Museum Heritage Certificate can confirm build date, despatch date, engine and body numbers, colour and factory-fitted equipment.
Look for invoices and photographs covering any restoration, especially chassis and bodywork.
Ask about import dates and right-hand-drive conversion work on US cars, and who carried it out.
MOT history and any club valuation or inspection reports.

On the test drive

Start from cold if possible and listen for rattles that persist, and watch for smoke.
Check oil pressure once the engine is warm, both at tickover and on the move.
On a PI car, see whether it restarts cleanly when hot after a short stop.
Pull through the gears and listen for layshaft rumble in second and third that disappears in top.
Try the overdrive in every gear it should work in and check it engages and disengages promptly.
Accelerate and lift off sharply on a quiet road to listen for clunks from the rear.
Feel for wandering, pulling or vague steering, and brakes that pull to one side.
Drive over uneven surfaces and listen for knocks from the suspension.
Afterwards, look underneath for fresh oil and coolant leaks.

Buying at auction

Plenty of TR6s pass through UK auctions, including Mathewsons in North Yorkshire. Buying this way can work well, but you must do your homework during viewing because the checks are limited and the hammer falls fast.

What you can check in viewing week

Look underneath with a strong torch, concentrating on the rear trailing arm mounts, the chassis around the differential, sills and floors.
Use a magnet on the front wings, rear wings, sills and lower B-posts to find filler.
Check the commission number and engine number against the V5C and the catalogue, and note the prefix.
Check the oil level and colour, and the coolant level and condition.
Ask whether the car can be started. If it can, listen for rattles and watch for smoke.
If allowed, push and pull the crankshaft pulley to check for excessive end float.
Look at the door gaps, panel fit and quality of paint.
Read every document in the paperwork file, including MOT history and restoration invoices.

What you usually cannot do

You usually cannot test drive the car, so gearbox, overdrive and rear axle noises go unheard.
The car usually cannot be lifted, so parts of the chassis remain out of sight.
Fuel injection behaviour when hot and on the move is hard to judge.
Brakes and steering cannot be properly tested.

Tips

Read the catalogue description critically. Words such as "believed", "reported" and "said to be" mean the auction house has not verified the claim.
Check whether a car described as a PI is a factory CP or CR car or a converted US car, and whether the description says so.
Remember that a buyer's premium is added to the hammer price, plus VAT where it applies. Read the terms before bidding.
Set your limit before the sale, including premium, transport and likely repairs, and stick to it.
Assume the car will need some work, especially if it has been standing.
Arrange transport home in advance. A car you have not driven should be trailered or carried rather than driven home.
Check insurance cover is in place from the moment you take ownership.

What makes one more desirable

Original UK right-hand-drive fuel-injected cars, particularly early 150bhp CP series cars, are the most sought after.
Honest, well-documented originality, including matching numbers and a Heritage Certificate.
Factory options such as overdrive, a factory hardtop and wire wheels.
Quality of chassis and body restoration, supported by photographs and invoices.
Well-converted US cars appeal to buyers who prefer to drive rather than show, but they are a different proposition from a genuine UK car.
Original colour schemes and correct interior trim.
Long-term ownership history and club involvement.

This guide does not give values or predict prices.

Selling a Triumph TR6

TR6 buyers are well informed and will check the same weak points described in this guide. Selling successfully means being open about what you have.

Preparing the car

Clean the car thoroughly, including the underside and engine bay.
Fix small faults such as blown bulbs, leaks and electrical niggles.
Ensure it starts easily and runs well, especially if it has fuel injection.
Take clear photographs of the underside, chassis, trailing arm mounts and interior.
Consider an independent inspection to reassure buyers.

Paperwork

V5C in your name with correct commission and engine numbers.
Heritage Certificate, if you have one.
Service records, invoices and restoration photographs.
MOT certificates and history.
Import and conversion records for US cars.

Where to sell

Club classifieds and magazines, such as those of the TR Register, which reach informed buyers.
Classic car auctions, including regional houses such as Mathewsons.
Specialist dealers, either as a sale or part exchange.
Classic car websites and private sale listings.

Writing the description

State clearly whether the car is a factory CP or CR fuel-injected car, a CC or CF carburettor car, or a converted car.
List chassis and body work with dates and who carried it out.
Describe any non-original parts, such as engine, dampers, fuel pump or seats.
Be specific about faults; vague descriptions put off serious buyers.

Living with one

Parts supply is very good, from mechanical parts and trim to complete replacement chassis.
A large specialist network across the UK understands these cars, including the fuel injection.
The TR Register and other Triumph clubs offer technical advice, events and access to knowledge.
The car is a two-seater with a reasonable boot, suiting touring as well as short trips.
Every TR6 is now more than 40 years old, so it can qualify for historic vehicle tax and MOT exemption, subject to the rules on substantial changes. Many owners still have an annual MOT or inspection for peace of mind.
Classic insurance with agreed value and limited mileage is widely available and often reasonably priced.
Regular use and servicing keep the injection system, brakes and seals in better health than long storage.

Clubs and registers

Questions people ask

What are the main problems with a Triumph TR6?

Rust in the chassis, especially around the rear trailing arm mounts and differential, and in the sills, floors, wings and rear deck. Mechanically, watch for worn crankshaft thrust washers, fuel injection set-up problems on PI cars, driveshaft and differential mount clunks, and gearbox layshaft bearing wear.

How can I tell a genuine UK PI car from a converted US car?

Check the commission number. Factory fuel-injected cars have CP or CR prefixes, while US carburettor cars have CC or CF. A Heritage Certificate from the British Motor Museum can confirm the car's original specification.

What is the difference between the CP and CR TR6?

The CP series ran until the end of the 1972 model year and was rated at 150bhp. The CR series that followed had a milder camshaft and was rated at 125bhp, along with a chin spoiler, new instruments and, later, standard overdrive.

Is a US import TR6 worth considering?

It can be, especially if the chassis is sound. Many US cars have less rust than UK cars, but they have less power in standard form and conversions vary in quality. Judge each car on its condition and describe it honestly.

How do I check the crankshaft thrust washers?

With the engine off, push and pull the front crankshaft pulley and watch it while someone presses the clutch. Visible movement suggests worn thrust washers; a specialist can confirm and advise.

Is the TR6 a good first classic?

It can be, provided you buy a car with a sound chassis and have access to a specialist. It is simple and well supported by clubs and parts suppliers, but rust and fuel injection need knowledge.

Which TR6 should I buy?

Buy on condition first. Original UK PI cars are most sought after, while well-sorted US cars can suit those who mainly want to drive. Overdrive is a worthwhile feature for touring.

Did all TR6s have overdrive?

No. Overdrive was an option for most of production and became standard around the 1974 model year. Early cars used the A-type, later cars the J-type.

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.