There's no single cut-off
Part of our guide to buying a used car. Mileage on its own doesn't tell you much — 80,000 miles is unremarkable on a 10-year-old motorway commuter car and a genuine concern on a 2-year-old one. The honest starting point: the average is a little over 7,000 miles a year (England's figure — the standard benchmark the UK motor trade uses; more on the source below), so multiply a car's age by that to get a rough expected figure, then read the rest of this guide before treating any single number as a verdict.
The quick rule of thumb — age × average annual mileage
The Department for Transport's National Travel Survey (table NTS0901) puts the England average at around 7,100 miles per car per year (2024 figures). DfT publishes this at England level rather than full-UK, since Scotland, Wales and Northern Ireland run their own separate transport surveys, but it's the figure the UK motor trade treats as the de facto national benchmark. Multiply that by the car's age and you get a rough expected mileage — a 5-year-old car might reasonably show somewhere around 35,000 miles, a 10-year-old car around 71,000.
Treat this as a starting point, not a formula to apply rigidly. It's a fleet-wide average — plenty of genuine, honestly-driven cars sit well above or below it depending on how they were actually used.
What counts as high mileage, by age
A car well above the age-adjusted average isn't automatically a problem, but it's worth knowing when a figure is genuinely unusual rather than just higher than the fleet average. Newer cars, in particular, tend to rack up more miles than the all-ages average suggests: RAC Foundation analysis of MOT test data puts the average annual mileage for cars under three years old at around 8,460 miles — noticeably higher than the 7,100 all-ages figure, largely because newer cars are disproportionately company/lease vehicles doing longer commutes.
The widely-quoted 100,000-mile mark matters more as a perception threshold than a mechanical one — see the next section — but it's worth knowing where the "is this a lot" instinct kicks in for most buyers, because it affects resale value and finance terms even when the car itself is mechanically fine.
Is 100,000+ miles a dealbreaker?
Not on its own. A well-maintained modern engine can comfortably run well past 150,000-200,000 miles — the mileage matters far less than whether the servicing was kept up. That said, a few practical things are worth checking around the 100k mark specifically:
- Cambelt (timing belt) replacement is a major service item often due around this mileage on many cars (also commonly age-based, roughly every 5-10 years depending on the manufacturer) — ask if it's been done, since UK garage pricing typically runs £300-£1,000 including parts and labour, depending on the car and whether a water pump is replaced at the same time (premium marques often cost more), and a failed cambelt on an interference engine can cause serious engine damage.
- Diesel Particulate Filter (DPF) condition is worth asking about on diesels, particularly if the car's history suggests mostly short, low-speed trips (more on this below).
- Finance and warranty availability can narrow past 100,000 miles or a certain age, purely as a lender/insurer risk-appetite matter, not a reflection of the car's actual condition. Worth checking before you fall for a specific car, not after.
None of this is financial advice — check the specific terms available to you before assuming a mileage figure rules a car in or out.
Why the type of mileage matters as much as the number
Steady motorway miles generally cause less mechanical wear — on the engine, clutch and brakes — than the equivalent number of stop-start urban miles, which is general mechanical consensus rather than a precisely quantified rule. A car's likely usage pattern is worth a look alongside the raw figure: a previous keeper who was a sales rep covering long distances built a different kind of wear than the same mileage racked up on a school run.
Service history notes and the pattern of MOT advisories over time are a better read on this than the mileage figure alone — worn brake pads and discs coming up repeatedly point to more urban use; a clean, consistent record over high motorway-style mileage is often a healthier sign than a lower figure with a patchy history.
How to check whether a car's mileage is genuinely consistent with its age
Everything above assumes the mileage on the clock is genuine. That's a different question from whether it's reasonable — this page is about the second question. If you think a figure might have been altered rather than just being higher or lower than average, see our guide to mileage clocking instead.
To check a specific car's reading looks consistent with its age, our free car check pulls the full MOT history — including the mileage recorded at every test — from just the registration, alongside the car's tax status. Looking at the year-by-year trend, not just today's single reading, is the real test: a steady, plausible climb across several tests tells you far more than one number in an advert ever can.
Where the MOT or service history is thin — a younger car with few tests, or a car that's changed hands more than once — our Comprehensive check cross-references the mileage against a wider set of industry records, useful where the free check's MOT trail alone doesn't give you enough history to judge. You can see exactly what one covers in this sample report.
Can a car have too little mileage?
Yes — very low mileage isn't automatically a green flag. A car that's sat unused for long periods can develop its own problems: seals and rubber components perish rather than wear, fluids degrade sitting still rather than circulating, and on diesels specifically, a DPF needs sustained higher-speed running to regenerate properly — one driven mostly on short trips or left standing for long stretches is more prone to DPF issues than one doing regular, longer runs. If a car's mileage looks unusually low for its age, it's worth asking directly about how and how often it was actually driven, and whether it's had genuinely long periods of storage.
What matters more than the number
A clean, consistent service history and a sensible pattern of MOT advisories over time tell you more about a car's real condition than its mileage figure alone — a dedicated guide to what good service history looks like, and a companion guide to common faults by car age, both go into this in more depth. Mileage is a useful starting filter, not the final word.
FAQs
What mileage is considered too high for a used car?
There's no fixed cut-off. As a rough starting point, multiply the car's age by the UK average of around 7,100 miles a year — a figure well above that isn't automatically a problem, but it's worth knowing when a reading is unusual rather than just above average, and checking the car's history rather than judging on mileage alone.
Is 100,000 miles too many for a used car?
Not on its own. Modern engines can comfortably run well past 150,000-200,000 miles with proper maintenance. The 100,000-mile mark matters more for resale value and finance-approval perception than as a mechanical limit — worth checking cambelt history and DPF condition (on diesels) around that mileage, but not a dealbreaker by itself.
What's a good average mileage per year for a car in the UK?
Around 7,100 miles a year (DfT National Travel Survey, England, 2024 figures — the figure the UK motor trade treats as the standard benchmark, since the devolved nations don't publish an equivalent), though newer cars — often company or lease vehicles doing longer commutes — tend to average noticeably higher, around 8,460 miles a year for cars under three years old.
Does high mileage matter more than a car's age?
Neither on its own tells the full story — they only mean something together, and a service history that shows consistent maintenance matters more than either. A high-mileage car maintained properly is often a safer bet than a low-mileage car that's sat unused and neglected.
Can a used car have too little mileage?
Yes. Very low mileage can mean a car that's sat unused for long stretches, which brings its own problems — perished seals, degraded fluids, and on diesels, a higher risk of DPF issues from insufficient sustained running. Ask directly how and how often the car was actually driven.
How do I know if a car's mileage is genuine, not just plausible for its age?
Run our free car check and look at the year-by-year mileage trend across the MOT history, not just today's reading — a steady, consistent climb is the best free evidence of a genuine figure. If something looks off, our guide to spotting mileage clocking covers the specific red flags.