BMW M8 Competition Convertible

A four-seat fast convertible

The BMW M8 Competition Convertible is the open-top F91 version of the M8, which went on sale in 2020 and is built at the Dingolfing plant in Bavaria. Our catalogue lists a 4.4L twin-turbo V8 petrol engine (the S63) producing 617 bhp and 750 Nm, with 0 to 100 km/h in 3.3 seconds and a 250 km/h limited top speed, sent through the M xDrive all-wheel-drive system. We have not driven this model for this article. This is a desk-researched ownership guide built from the BMW Group launch press release for the M8 range, a PistonHeads used buying guide published in May 2024 and the government recall check. The PistonHeads guide is written about the M8 Competition Gran Coupe and covers the Coupe and Convertible only in passing, so we treat it as a family guide: the mechanical reports apply to every Competition, but body and interior points are for the four-door and may not match the convertible.

The figures are consistent with the sources. BMW's release gives 460 kW and 625 hp for the Competition models, which is the metric rating that converts to the 617 bhp in our catalogue, and 750 Nm of torque (553 lb ft). It quotes 3.3 seconds from 0 to 100 km/h for the Competition Convertible, against 3.2 seconds for the Competition Coupe. The 250 km/h limit is the standard electronic limiter; PistonHeads says the M Driver's Package raises it to 190 mph and that M Pro, an option pack, includes a raised limiter and carbon ceramic brakes.

What the Competition adds

BMW's launch release describes the engine in the Competition models as the most powerful ever developed for an M GmbH car, with peak torque sustained up to 5,800 rpm and maximum output at 6,000 rpm, and a special engine mounting for crisper response. The engine is paired with an eight-speed M Steptronic automatic and the M xDrive all-wheel-drive system. PistonHeads says the Competition has a rear differential with an active locking function and a driveline that can switch to rear-wheel drive. It adds that BMW chose to use conventional steel springs and adaptive dampers, without air suspension, active anti-roll bars or four-wheel steering. The author sees the absence of air springs as a plus for reliability, and the cars have an extra Track mode.

BMW describes a multi-layer fabric roof that opens and closes in 15 seconds at the touch of a button, even on the move. That roof is the thing that separates this car from the Coupe, with its carbon fibre roof, so give it extra attention when you inspect a car.

Engine and gearbox

The guide praises the S63's torque spread and says the ZF 8HP automatic converts it well. It is not a dual-clutch gearbox, since BMW began to phase those out at the start of the 2020s. The author found the engine note more restrained than an AMG V8 but noisy on the overrun. PistonHeads quotes 3.2 seconds for the Gran Coupe it reviews, while BMW's own figure for this Convertible is 3.3 seconds, as noted above. On damp roads the guide reports that launch control can light up all four tyres.

Reliability is described as outstanding so far, with very little evidence of anything major or even minor going wrong with any M8 variant. That is a report on a model that was only a few years old in 2024, so a clean record on paper still needs checking on the car. The guide says official combined fuel consumption is 26.9 mpg, that spirited driving reduces it to the low twenties and that the fuel tank is on the small side for long continental trips. BMW Service Inclusive covered the first four years of maintenance on new cars, and the author could not find any independent M8 specialists in the UK, so find out where the car was serviced and by whom.

Chassis, brakes and tyres

The guide says the suspension hardware is mainly from the M5 with settings specific to the M8, with more front negative camber, rear ball joints in place of rubber bushes and stiffer engine mounts. It recommends leaving the suspension in Comfort on British roads, and says some people find the Porsche 911 rides better every day. The M8 is wide, so check the wheels for kerb damage.

The standard tyre is the Michelin Pilot Sport 4S. Look at the tread across all four tyres, ask when they were last replaced and whether the car has been on track. Carbon ceramic brakes came with the M Pro pack and with the Ultimate pack, which PistonHeads says builds on M Pro and adds most of the remaining options, so find out which brakes the car has and inspect the discs, pads and any wear warning. Expect replacement ceramic parts to cost a good deal more than iron ones.

Body, roof and electronics

For this car, begin with the fabric roof. Run it up and down several times with the engine on and off, listen for hesitation or noise, and look at the seals, the stitching and the headlining for marks that could point to water getting in. This is our own inspection list, because the PistonHeads guide does not report convertible-roof faults.

PistonHeads reports some Gran Coupe cars had part of the reverse camera image obscured, or a screen that failed to light when reverse was selected. The rear window is shallow and the rear visibility poor, so check the camera, parking sensors and every screen in the car. Voice control was not particularly responsive, gesture control worked, Android Auto connects wirelessly and the wireless charging pocket is too small for many phones in cases. The 2022 update added a 12.3-inch screen and optional M3 and M4-style carbon bucket seats. The guide notes that the wing vents are decorative and that a full set of option packs adds a great deal to the car, so compare carefully.

Recalls and history

PistonHeads says M8 cars were recalled in the United States in 2023 for an electrical fault that allowed the windows to close after the key was removed, and mentions recalls for an airbag fault, incorrectly welded brake parts and a transmission wiring harness. As far as the author could tell, UK Competition cars were not included in those. That is the author's reading, not a guarantee. Enter the registration in the DVSA recall service and ask the seller for dealer paperwork showing that any open work has been completed.

Buying decision

The guide's verdict, written about the Gran Coupe, is that the M-tuned car gave thrust on demand while still being comfortable enough for family journeys, and it says the biggest depreciation had already happened by May 2024. As of that May 2024 article it said the M8 run was scheduled to end in mid-2025, and that these would very likely be the last combustion-engined 8 Series M cars. Most of its reliability praise concerns a different body style, so treat the Convertible as less proven. The prices it gives were dated May 2024, so we have not repeated them. Compare several current adverts for mileage, options, roof condition and service history.

The best car has a full BMW service record, a roof that works smoothly without any trace of leaks, a working camera and screen set, even tyre and brake wear, and every recall closed. If the seller cannot show these, treat the car as a risk: it has a complex roof and a heavy open-top V8 body, and the Convertible has a shorter track record than the Coupe.