Repair decision tool
Is my car worth fixing?
The 50% rule
If a repair costs more than half your car’s value, think hard. More than its full value — walk away.
A car is usually worth fixing when the repair bill is under half its market value — a £600 clutch on a £4,000 car is an easy yes. Between 50% and 100% of the car’s value, only fix it if the rest of the car is sound and you plan to keep it. Above 100%, selling as-is or scrapping almost always wins. Use the calculator below to get your verdict, then compare real quotes before deciding.
Worth fixing — or time to sell? Run your numbers
Slide to your car’s rough value (a guess within £500 is fine — check a free valuation site if unsure), pick the repair you’re facing, and choose the garage type. The verdict uses the mid-point of typical UK prices for that repair; your exact car may sit lower or higher, which is what the reg check is for.
Fix it
Typical repair bill
£520 – £1,400Half your car’s value
£1,750Bill vs car value
27%Verdicts use the mid-range independent price. Dealer prices run about 50% higher. Price ranges are estimates — final quotes come from garages. We may earn a commission when you book through our partners, at no cost to you.
Compare quotes from local garagesThe 50% rule, explained properly
The rule is simple: when a single repair costs more than half what your car is worth, the maths starts working against you. A £1,200 head gasket on a £2,000 car means you’re spending 60% of the car’s value to keep it — and the car isn’t worth £1,200 more afterwards. Buyers pay for the car, not for its repair receipts. A fresh clutch might add a few hundred pounds of confidence to a sale; it never adds its own cost back.
Below 30%, fixing is nearly always right. Replacing a car costs far more than people budget for: a comparable used car means dealer margin, an unknown history, and often its own looming repairs. The car you own is the car you know. Spending £600 to keep a £4,000 car you trust beats gambling £4,000 on someone else’s problems.
The rule breaks down at the edges, and honesty matters here. A cambelt on a £1,400 city runabout can breach 50% and still be worth doing — it’s prevention, and the alternative is engine destruction. A £700 repair on a car that also needs tyres, brakes and a service soon is really a £1,400 decision. Always count the whole car, not the single bill. The sections below cover both edges.
Real examples: five drivers, five verdicts
These are typical UK scenarios using independent-garage mid-range prices. Same repair, different car value — completely different answer.
| Scenario | Car value | Typical bill | Bill vs value | Verdict |
|---|---|---|---|---|
| Clutch kit on a family hatchback | £4,500 | £600 | 13% | Fix it — easy decision |
| Cambelt on an older supermini | £1,800 | £520 | 29% | Fix it — prevention beats a destroyed engine |
| Clutch + DMF on a diesel estate | £2,400 | £870 | 36% | Fix, but get quotes — shop the price hard |
| Head gasket on a high-mileage supermini | £1,500 | £960 | 64% | Think hard — only with a clean diagnosis and plans to keep it |
| Automatic gearbox on an ageing crossover | £1,200 | £1,500 | 125% | Don’t pay this — sell as-is or scrap |
Bills shown are mid-range independent prices; dealer quotes run roughly 50% higher, which can flip a verdict on its own. That’s an argument for comparing quotes, not for skipping the repair.
The repairs that trigger this question
Nobody googles “is my car worth fixing” over a £90 bulb and a wiper blade. It’s the four-figure quotes that force the maths. These are the usual suspects, with typical UK independent prices and where to dig deeper:
| Repair | Typical range (independent) | Why it’s a verdict-maker | Full price guide |
|---|---|---|---|
| Head gasket | £520 – £1,400 | Labour-heavy; often appears on older, lower-value cars | Head gasket costs |
| Gearbox (major repair) | £500 – £2,500 | Widest range of any repair; diagnosis quality decides everything | Gearbox repair costs |
| Clutch + flywheel (DMF) | £650 – £1,090 | The DMF add-on nearly doubles a clutch bill | Clutch & DMF costs |
| Clutch kit | £450 – £750 | Common on cars old enough to be worth little | Clutch costs |
| Turbo (reconditioned) | £550 – £1,300 | Often quoted new when a recon — or a £60 pipe — would do | Turbo costs |
| Cambelt kit | £280 – £750 | Preventive — skipping it turns into an engine bill | Cambelt costs |
Ranges span small hatchbacks to premium models. Your exact car sits at a specific point in each range — enter your reg below for that number.
When fixing is the right call
The fault is discrete and the rest of the car is sound. One failed component on a car with good history, solid MOT record and no rust is the best case for repairing. A clutch is a wear item, not a verdict on the car. Fix it and you know exactly what you own — which is more than you can say about any replacement car.
The repair buys years, not months. A new cambelt resets a five-year clock. A recon gearbox typically carries a 12-month warranty and outlasts it comfortably. Compare that with spending the same money on a slightly newer car of unknown history — with its own cambelt due and its own clutch wearing.
Replacing costs more than it looks. The true cost of changing cars isn’t the sticker price difference: it’s dealer margin, the risk premium of unknown history, possibly higher insurance and tax, and the near-certainty that a used replacement arrives with its own deferred maintenance. £900 spent on the devil you know is often the cheapest motoring available.
You’d struggle to replace it for the money. If your car would fetch £1,500 and its replacement budget is £2,000, you’re shopping the riskiest end of the used market. Fixing a known car for £700 beats buying an unknown one for £2,000 more often than the raw percentages suggest — this is the honest argument against over-applying the 50% rule.
When to walk away — and the sunk cost trap
The bill exceeds the car’s value. This is the bright line. A £1,500 gearbox on a £1,200 car means you could buy the same car, working, for less than the repair. The only exceptions are genuine rarities and cars with real sentimental value — and then you should decide with open eyes that you’re paying for attachment, not economics.
This repair is one of a queue. Check your MOT history before deciding: three advisories waiting their turn mean the real bill is the sum, not this quote. A £600 clutch on a car that also carries corroded-brake-pipe and worn-suspension advisories is a £1,400 decision wearing a £600 mask.
You’re chasing money already spent. “I’ve just put £800 into it” is the most expensive sentence in motoring. Money spent last month is gone regardless of what you decide today — the only question that matters is whether the next pound is better spent on this car or a different one. If this is the third big bill in a year, the car is telling you something.
If you don’t fix it: scrap, sell as-is, or part-exchange
A “don’t fix” verdict isn’t the end of the story — a broken car still has three routes to money, and they pay very differently. Scrap value is a floor, not a target: a car that starts and drives, even badly, is nearly always worth more sold as-is than weighed in.
| Route | What you typically get | Effort | Best when |
|---|---|---|---|
| Scrap (authorised treatment facility) | £150 – £400 by weight | Lowest — collected, paperwork simple | Car doesn’t run, or repair bill dwarfs its value |
| Sell as-is (“spares or repair”) | Usually well above scrap | Medium — honest listing, tyre-kickers | Car runs; the fault is known and stated |
| Part-exchange with the fault declared | Trade value minus repair, roughly | Low — dealer handles everything | You’re buying your next car anyway |
| Fix, then sell | Rarely recovers the repair cost | Highest — you fund the repair first | Cheap cosmetic fixes only; mechanical repairs seldom pay back |
Legal notes: scrapping must go through an authorised treatment facility (payment by bank transfer — cash for scrap cars is illegal in England and Wales), and you must tell DVLA or risk a fine. Selling as-is, you must honestly describe faults you know about; “sold as seen” doesn’t license hiding a dead gearbox.
Before you decide anything: is the diagnosis even right?
The worth-fixing maths is only as good as the diagnosis feeding it — and the most expensive repairs have cheap impersonators. A “head gasket” that was never block-tested might be a £90 thermostat. A “failing turbo” is a split boost pipe surprisingly often. A “gearbox on its way out” can be a £250 clutch cable or low oil. Ask the garage: “what test confirmed this diagnosis, and can I see the result?” A garage confident in its diagnosis will show you; a garage guessing will bristle.
For any bill that fails the 50% test, a second opinion costs £50–£90 of diagnostic time and can save four figures. That’s the best-value hour in motoring. And if the diagnosis stands, you’ve lost nothing — you now have two quotes to compare instead of one.
Whatever you decide: how to pay less
Never accept the first quote on a four-figure repair. The spread between garages for the same job on the same car routinely exceeds £300 — more than most people save by agonising over the fix-or-sell decision itself. Comparing quotes is the single highest-value step on this page.
Ask about reconditioned parts. Gearboxes, turbos and cylinder heads all come as professionally rebuilt units with warranties, typically 30–50% below new. For a car worth £3,000, a recon part is nearly always the rational choice — you’re matching the part’s remaining life to the car’s.
Bundle labour where jobs overlap. If the gearbox is coming out, the clutch is nearly free to do at the same time; if the cambelt is off, the water pump costs only the part. Doing queued jobs together can save hundreds in shared labour — and changes the worth-fixing maths in the car’s favour.
Time it around your MOT. A repair you’d deferred becomes urgent when it’s also an MOT failure. Checking your MOT costs and history before committing to a big repair tells you whether you’re one bill or three away from a clean sheet.
Same repair, same car — quotes £300 apart is normal. See what garages near you would charge before you decide anything.
Compare live quotesFrequently asked questions
How do I know if my car is worth fixing?
Compare the repair bill to your car’s market value: under 50% of value, fixing usually wins; over 100%, selling or scrapping wins. Between the two, it depends on the car’s overall condition, its MOT history, and how long you plan to keep it. Get a free valuation, a firm quote, and run the numbers in the calculator above.
What is the 50% rule for car repairs?
The 50% rule says a repair costing more than half your car’s value deserves serious hesitation — because the repair doesn’t add its cost back to the car’s worth. It’s a threshold for thinking, not an automatic no: preventive jobs like cambelts and discrete faults on otherwise sound cars can justify crossing it.
Should I fix my car or scrap it?
Scrap only when the car doesn’t run and the repair costs more than the car is worth — scrap yards pay £150–£400 by weight regardless of the model. A car that starts and drives is nearly always worth more sold as-is with the fault declared. Fix it when the bill is under half the car’s value and the rest of the car is sound.
Is it worth fixing a head gasket?
A head gasket typically costs £520–£1,400 at an independent garage, so on cars worth under £2,000 it often fails the 50% test. Before deciding anything, insist on a block test — overheating and coolant loss have cheaper causes, and paying four figures on a guessed diagnosis is the real mistake.
Is it worth repairing a gearbox?
Gearbox bills run £500–£2,500 depending on whether it needs a repair, a rebuild or a replacement — the widest range of any common repair. On a car worth £3,000+, a reconditioned unit with a warranty usually makes sense. Rule out cheap causes first: low oil, a worn clutch, or a £60 sensor can mimic gearbox failure.
What repairs cost more than a car is worth?
On cars valued under £1,500, almost any four-figure job can exceed the car’s value: automatic gearbox failures, head gaskets, turbos, and engine rebuilds are the usual culprits. That’s why the same fault is an easy fix on a £6,000 car and a scrapping decision on a £1,000 one — the repair price barely changes, the maths completely does.
Should I repair my car before selling it?
Mechanical repairs rarely pay back at sale — a £700 clutch might add £300 to the price. Cheap, visible fixes are different: a £15 bulb, a £60 tyre or a fresh MOT can add more than they cost because they remove buyer objections. Fix what’s cheap and visible; declare what’s expensive and mechanical.
Can I sell a car that needs repairs?
Yes — listing it as “spares or repair” with the fault honestly described is legal and common, and typically pays well above scrap value. You must not misrepresent faults you know about, and if the car is dangerous to drive you should say so and expect the buyer to collect it by trailer.
How much do you get for scrapping a car in the UK?
Typically £150–£400, driven by the car’s weight and current scrap metal prices rather than its model or condition. It must go through an authorised treatment facility, payment must be by bank transfer (cash for scrap cars is illegal in England and Wales), and you must tell DVLA or risk a £1,000 fine.
Does a new clutch add value to a car?
Not meaningfully — buyers pay for the car, not its receipts. A documented new clutch makes a sale easier and defends your asking price, but it won’t raise the price by anything near the £450–£750 the job costs. Repair for your own use, not as a sale investment.
Is it worth fixing a car that failed its MOT?
Usually yes — most MOT failures are routine items like brakes, tyres, suspension and lights costing far less than people fear. It stops being worth it when the failure list is long and structural (corrosion, multiple suspension components) on a low-value car. Price the full list, not just the scariest item, then apply the 50% test to the total.
Is it cheaper to keep an old car running or buy a newer one?
Keeping a paid-off car running is nearly always cheaper per year — even £600 of annual repairs undercuts the depreciation alone on a newer replacement, before finance costs. The balance tips when repairs become frequent rather than occasional, or when a single bill exceeds the car’s value.