Oil and coolant leaks (hot vee)
The hot vee turbo placement runs the V8 hot and stresses gaskets, hoses, and seals.
How to check
Inspect for leaks at valve covers, turbo oil lines, and the cooling system.
$1,500est. repairMedium severity
BMW M850i G14 facelift
2023 to 2026ConvertibleM Performance
64Guide Score 64Good$3,012 a year to ownProvisional: 25 to 54 of 69
- Best year
- 2026
Photo: Alexander Migl, CC BY-SA 4.0, stand-in pre-facelift M850i convertible, no free facelift front shot available, plate blurred, via Wikimedia Commons
The short answer
The M850i G14 Convertible post-LCI gets the same light facelift for 2023 as the coupe: a standard illuminated kidney grille and a larger 12.3 inch central screen (iDrive 7).
The score, part by part
64Guide Score for 2026Goodabout $3,012 a year to own
- Place among the 69 generations
- Provisional: places 25 to 54 of 69
- Likely score range
- 57 to 76
- Confidence
- Low
- Acclaim
- 43 of 100
- Chance of a bill over $10,000 in five years
- under 0.1%
The seven parts and acclaim, 2026 model year
- Heritage counts 15 of 100
- 324% of it not measured
- Engine counts 15 of 100
- 46
- Drive feel counts 20 of 100
- 68
- Analog connection counts 10 of 100
- 64
- Weight counts 10 of 100
- 42
- Long-term value not scored
- not measured
- Ownership counts 17 of 100
- 70
- Acclaim counts 15 of 100
- 43
Each part is scored from 0 to 100 on a fixed outside scale. Acclaim comes from published expert lists, launch reviews and awards; the more acclaimed a car, the less its ownership cost counts in this all-time score (its dollars below are unchanged). A part marked not measured carries no weight for this car, and the others share its weight.
Long-term value, shown and not scored
No permitted price yet: we have not found three prices for this car from sources that allow this use.
Long-term value starts to count in the score once 75% of the 69 generations have permitted prices. Today 43 do.
The cost to own
About $3,012 a year to own ($2,014 to $4,546), about $14,034 over five years, bought at five years old or its own age if older, kept five years.
Expect about $2,000 to $4,500 a year; the bills that decide it are oil and coolant leaks and valve stem seals. Ownership risk: moderate.
Guide Score method v5-final.14, an editorial score built only from permitted, sourced data. How it works.
N63 V8 (TU3)523 hpAWD8-speed automatic17 city, 24 hwy mpg
Colors it came in, most wanted first. Pick one to see the page in it.
- Routine service a year, estimate
- $600 to $950
Best year to buy
2026The best year to buy, reading 64 of 100, about $3,012 a year to own.
No logged change between model years sets it apart; every year reads within 2 points of it, so buy on condition and records.
No year to think twice about: none reads 3 or more points below the 2026, and no logged fault separates them.
From our log of the changes between model years, each with its source. Only changes the score reads count as reasons; recalls BMW fixes for free, options and tuning notes do not. The cost a year is for a car bought at five years old, or its own age if older, kept five years. How the score works.
The longer answer
Convertible note applies, heavier, less rigid, cruiser focused. The 8 Series ended production in April 2026 with no successor announced; 2026 is the last model year.
What to look for
- Same checks as the pre-LCI convertible plus the latest iDrive software
- Check that the illuminated grille works and that the top cycles fully
- On 2023 cars, check that recalls 23V-099 and 23V-821 are done
Holds value
- Bowers and Wilkins Diamond audio
- Individual paint
- Working top mechanism
- Low mileage
- Complete records
Hurts resale
- Top mechanism faults
- Accident damage on a near new car
- Missing service records
Known issues to check
What goes wrong on this generation, roughly what a fix costs at an independent shop, and how to spot it before you buy. Every M850i generation compared.
Approximate proportions
Cooling on the 2026 car
- Oil and coolant leaks (hot vee)Medium$1,500
Inspect for leaks at valve covers, turbo oil lines, and the cooling system.
- Cooling system loadMedium$1,500
Verify cooling parts have been refreshed past 80k mi, ask if owner has run 5k to 7.5k oil intervals.
5known issues
1NHTSA recalls filed as the M850i, 2023 to 2026
0owner complaints to NHTSA
NHTSA files some of this car’s recalls under the 8 Series, so they are missing here. Check yours by VIN at nhtsa.gov/recalls.
Cooling system load
The hot vee layout stresses radiators, hoses, the expansion tank, and the water pump. Shorter oil change intervals recommended.
How to check
Verify cooling parts have been refreshed past 80k mi, ask if owner has run 5k to 7.5k oil intervals.
$1,500est. repairMedium severity
Higher running cost than the inline six
Tires, brakes, and service all run higher than B58 cars. Budget accordingly.
How to check
Account for the higher annual cost when cross shopping against a six.
Variesno single repair costLow severity
Valve stem seals (older or tracked)
Worn valve stem seals are a known N63 and N63TU repair that drives oil consumption and startup smoke; no bulletin covers these later engines yet, but check for blue smoke at start-up on high-mileage cars.
How to check
Look for blue startup smoke, request a leakdown on high mileage cars.
$4,000est. repairMedium severity
Oil consumption (N63)
The N63 family is known to consume oil between changes. Improved on the TU2 and TU3 in these cars compared with the original N63 and the TU1 (2013 to 2019 550i, 650i, 750i, X5 and X6), whose oil consumption led to a 2022 class action settlement, but not zero.
How to check
Ask owner about oil top-ups between changes, review service records.
$1,500est. repairMedium severity
Ownership and safety
BMW of North Americal, LLC (BMW) is recalling certain 2023 8 Series Coupe (840i, 840i xDrive, M850i xDrive, M8), 8 Series Convertible (840i, 840i xDrive, M850i xDrive, M8), 8 Series Gran Coupe (840i, 840i xDrive, M850i xDrive, M8, Alpine B8 xDrive), 2 Series Coupe (230i, 230i xDrive, M240i xDrive, M2), and 2022-2023 Z4 sDrive30i, Z4 M40i vehicles. When the digital key is removed from the vehicle, the Electronic Control Unit (ECU) software may still allow the power windows and sunroof to be closed. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 118, "Power-operated Window Systems."
NHTSA files some of this car’s recalls under the 8 Series, so they are missing here. Check yours by VIN at nhtsa.gov/recalls.
Live from NHTSA, across the 2023 to 2026 model years.
What it costs to run
Our estimates at an independent shop, parts and labor; fuel from the EPA.
Fuel a yearEPA
~$2,240
At about 8,000 miles a year, our estimate for an M Performance car, the two-year budget's miles; 19 mpg combined, premium gasoline
Factory tiresEstimate
$1,600 to $2,200
20in staggered summer run-flats
Brakes, front and rearEstimate
$1,800 to $3,200
Pads and rotors, independent shop
Annual serviceEstimate
$600 to $950
Oil and inspections
Pricing tires for this car? Compare the factory sizes at Discount Tire, and ask a local shop to match it.
Maintenance schedule
- Oil serviceyearly or 10k mi~$250
- Brake fluidevery 2 yrs~$120
- Cabin microfilterevery 2 yrs~$90
- Spark plugsevery 60k mi~$500
- Tire set, wear itemevery 15k to 25k mi~$2,100
- Brake job, wear itemevery 25k to 40k mi~$2,500
Sources and methodwhat each figure covers
Fuel from EPA fueleconomy.gov: its yearly cost is for 15,000 miles with 55% city driving, moved here to the miles a year the two-year budget uses. The rest are our estimates at independent-shop and retail prices from September 2026. Service is a year of routine maintenance at 10,000 miles: one or two oil changes, brake fluid, filters, and spark plugs spread over their interval. Repairs are separate. Tires are a mounted set of summer tires; brakes are pads and rotors on both axles. Prices vary by region and shop.
Prices near you
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Set your ZIP and this page shows the asking prices of M850i G14 facelift cars listed for sale within 100 miles of you today, with the cars themselves.
What they sell for
$50,000lowest example
$78,000highest example
3listings tracked
2024 BMW M850i
Aventurin Red Metallic (Individual) · 12,000 mi · 8AT · AWD
$78,000listing score 76
2023 BMW M850i
Tanzanite Blue II (Individual) · 28,000 mi · 8AT · AWD
$65,000listing score 71
2023 BMW M850i
Alpine White · 52,000 mi · 8AT · AWD
$50,000listing score 53
Representative listings, last reviewed September 2026. Examples chosen by us, not a live feed.
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The cars this one gets weighed against, by lineage and by price.
Follow the M850i
The M Index, once a month: any change to the M850i's guide or score, with the reason, new recalls on M cars, and one thing to check before you buy.