BMW M8 Buying Guide: Common Problems and What to Check Before You Buy
The M8 is the flagship: the M5’s mechanical hardware wrapped in a grand-touring body, and the most expensive M car to buy and to put right. It gets used as a fast continent-crusher and, often, modified. None of that is automatically a problem. Undisclosed or poorly documented, it can be an expensive one.
The single most important thing to understand before buying any M8: a car’s history is not the same as its condition, and neither is fully visible in the car advert. A folder of receipts tells you what was paid for, not what was skipped. This guide walks through the range, what tends to go wrong, and what a car advert won’t tell you.
At a glance: the M8 range
| Body style | Code | Years | Engine | Drive | Transmission |
|---|---|---|---|---|---|
| Coupé | F92 | 2019–2025 | 4.4 twin-turbo V8 (S63) | M xDrive | 8-speed auto |
| Convertible | F91 | 2019–2025 | 4.4 twin-turbo V8 (S63) | M xDrive | 8-speed auto |
| Gran Coupé | F93 | 2019–2025 | 4.4 twin-turbo V8 (S63) | M xDrive | 8-speed auto |
The M8 shares the F90 M5’s S63 twin-turbo V8, 8-speed automatic and M xDrive, so much of the mechanical picture mirrors that car. Two UK notes: the M8 was sold here in Competition spec (625 bhp) only, no base 600 bhp cars were officially imported, and it was discontinued in the UK in early 2025. The Convertible (F91) uses a multi-layer fabric soft-top. This is the first production M8, so there’s no older generation to confuse it with.
Common problems and what to check
The V8 and driveline: shared with the F90 M5
Because the hardware is the F90 M5’s, the same checks apply: the coolant expansion tank can crack and leak onto the wiring and coils below (check for weeping), the hot-V S63 can use oil (check consumption), and the low-pressure fuel sensors are worth including in any diagnostic scan. Above all, the S63 rewards disciplined servicing, so scrutinise the service record.
Exposed auxiliary radiators
Because the M8 sits lower and wider than the M5, its low nose intakes leave the auxiliary radiators very exposed to stone chips. A single stone strike can cause slow, easily missed coolant loss, and on a hot-V turbo engine, overheating is expensive. Inspect the front radiators and coolers closely, and treat any coolant-loss history seriously.
Brakes, tyres and the convertible
A heavy GT goes through brakes and tyres; if carbon-ceramics are fitted (optional across all three body styles), price replacement in. On the Convertible (F91), operate the roof fully and check the seals and mechanism.
Specification, value and modification
The M8 is heavily optioned and expensive, so the gap between a well-specced car and a base one is large, confirming the spec matches the advert matters more here than almost anywhere. Establish any modifications, and confirm the infotainment, cameras and driver-assist features all work on the test drive.
Beyond the mechanicals: history and provenance red flags
Two cars with identical engines can be worth thousands apart on history alone. Before you focus on mechanical condition, the paper trail has to stand up:
- Service history gaps: especially around major-service intervals. Missing stamps aren’t automatically disqualifying, but they change the price.
- Mileage that doesn’t add up: MOT records should tell a consistent story year-on-year. A jump or a stall is worth understanding before you view.
- Outstanding finance: a car can’t be sold cleanly with money owed against it. This is a five-minute check that prevents a very bad day.
- Accident or write-off markers: a recorded repair isn’t always a deal-breaker, but you need to know it’s there and price accordingly.
- Specification that doesn’t match the car advert: claimed options that aren’t actually fitted are common, and on an M8 the spec drives the value.
None of these require you to be in the same room as the car. All of them are checkable in advance.
What a car advert and a test drive won’t tell you
It helps to think of an M8 purchase as three layers of truth:
- What the seller says: the car advert, the description, the conversation. Useful, but unverified.
- What the records say: MOT and mileage consistency, finance, stolen and write-off markers. This is data verification, and it can be done before you travel.
- What only a physical inspection reveals: compression and leak-down results, suspension and bushing wear, transmission and driveline health (and the roof on a convertible), the things you can only find with the car on a ramp.
Most buyers do layer 1, skip straight to a test drive, and only reach layer 3 (a proper PPI) on the one car they’ve already half-committed to: sometimes after a long drive to see it. Doing layer 2 first is what stops you wasting a Saturday on a car whose history was never going to check out.
To be clear about the limits: data verification confirms a car is what it claims to be on paper. It does not replace a physical, mechanical pre-purchase inspection. The two do different jobs, and a careful M8 buyer does both: in that order.
How Chequered Past helps
Chequered Past is the layer-2 step. You give us the registration; we check the official records on that car: the factory spec, MOT and mileage consistency, outstanding finance, stolen and write-off markers, keepers and the value, and we’re explicit about anything we couldn’t confirm.
What it does: tells you, before you travel, whether a car is what it says it is. What it doesn’t do: replace a physical inspection of mechanical condition. We’ll always tell you where that line is.
Run a history check on an M8 you’re considering →
Frequently asked questions
Is the M8 just an M5 in a coupé body? Mechanically they’re very close: the M8 shares the F90 M5’s S63 V8, 8-speed automatic and M xDrive, and the same engine and driveline checks apply. The M8 is the grander, more expensive GT bodystyle (coupé, convertible or Gran Coupé), and in the UK it came in Competition spec only.
Are used M8s reliable? Treated well, the V8 is strong, but the M8 is a big, complex, expensive car, so condition, spec and maintenance history matter a great deal. The real risk is less the model and more how this car has been serviced, modified and driven.
Do I need the car’s registration? Yes. The free check and the £10 vehicle history check both run on the registration.
Can you check a modified or tracked M8? Yes. We surface the signals; you decide what they mean for you. The goal is an informed decision, not a pass/fail.
Other BMW M guides: BMW M buying guide hub
Chequered Past is an independent analysis service and is not affiliated with, endorsed by, or connected to BMW AG or any vehicle manufacturer. Data is drawn from licensed DVLA and DVSA records via our data provider.