Used BMW M5 F90 (2018-2023): Buyer's Guide

Owners on BimmerPost have reported the BMW M5 F90's plastic coolant expansion tank splitting at the cap threads with as few as 11,000 miles on the clock. That tank sits directly above the fuel injectors. When it leaks slowly and nobody catches it, coolant works its way onto the injectors underneath, and one documented case turned a cheap plastic part into a full injector replacement. This is the generation-defining thing to check on a car that otherwise has a genuinely strong reliability story compared to the M5s that came before it.

The F90 ran from the 2018 through 2023 model years, BMW's fifth M5 generation and the last one before a hybrid V8 took over for 2025. It's the M5 most people are shopping for used right now: six to eight years old, into the price range where a twin-turbo V8 sedan with over 600 hp actually looks like a deal, and just far enough removed from warranty that the coolant tank, the fuel system, and the tires start mattering more than the spec sheet. This guide covers what actually breaks, which model years carry recalls, and what to look at before you hand over a deposit.

This Generation at a Glance

The F90 is the M version of the G30 5 Series, and it's the first M5 sold exclusively with all-wheel drive from the factory. BMW calls the system M xDrive; every US-market F90, in every trim and every model year, left the factory with it. There was never a US-spec rear-wheel-drive-only F90 to shop for, though the drivetrain has a driver-selectable 2WD mode for burnouts and track days.

The base M5 launched for 2018 making 600 hp from a 4.4-liter twin-turbo V8 (BMW's internal code is S63B44T4, commonly shortened to S63TU). The M5 Competition arrived as its own model for 2019, adding 17 hp via a retune to 617 hp along with stiffer suspension tuning, no engine hardware changes. BMW gave the F90 a mid-cycle refresh for 2021: updated styling, revised infotainment, and a wireless CarPlay setup, with no change to either engine's output. The limited-run M5 CS landed for the 2022 model year only, bumping output to 627 hp and shedding roughly 230 lbs with carbon-fiber body panels, and BMW allocated only a few hundred units to the US market at an as-tested price north of $140,000 new.

Current pricing and inventory: BMW M5 market data, with per-year pages for 2018, 2019, 2020, 2021, 2022, and 2023.

Powertrain and Trim Breakdown

The S63TU 4.4L Twin-Turbo V8 (Every Trim)

Every F90, regardless of trim or model year, uses the same basic S63TU V8 architecture. The differences between M5, Competition, and CS are tuning and suspension calibration, not different engines, so the mechanical risks below apply across the board.

Owners consistently praise this engine for how usable it is: real low-end torque, a genuine sedan back seat and trunk, and enough tuning headroom that a simple ECU flash pushes well past stock output without touching the internals. BimmerPost and M5board.com threads describe it as the more "analog" and track-capable M5 compared to the hybrid G90 that replaced it, at the cost of being thirstier and higher-strung to maintain.

The coolant expansion tank is the generation's signature failure. The plastic tank is built from glued sections and sits under real pressure given the engine's output, and BimmerPost threads document tanks splitting at the cap or seam anywhere from 11,000 miles to well past 100,000. One documented 2019 Competition owner reported chronic low coolant starting around 48,000 miles that eventually reached the fuel injectors below the tank, requiring their replacement. The aftermarket has responded with billet aluminum and relocation-kit replacement tanks specifically because the OEM part is a known weak point. Watch for dried coolant crust around the tank cap or hose clamps on any inspection.

Rod bearing wear is real but less catastrophic than on older M engines. The S63TU doesn't carry the same reputation as the S54, S65, or S85 engines from earlier M cars. Per m5board.com technical discussion and independent writeups on the S63TU specifically, the leading cause of bearing wear on this engine isn't age or mileage alone, it's leaky fuel injectors letting raw fuel dilute the oil, which strips lubrication from the bearings over time. That means a low-mileage, garage-kept car isn't automatically the safer buy if its injectors have been quietly seeping. Preventive rod bearing replacement runs around $4,500 at BMW specialist shops; if bearings actually spin, expect a full engine-out repair.

The high-pressure fuel pump recall. NHTSA campaign 19V513000 covers 2019 M5s specifically: the fuel pump flange could crack and leak fuel, a fire risk, fixed free at any BMW dealer. Outside of recall work, fuel injector replacement on this engine runs $1,500 to $1,820 out of pocket, per RepairPal's cost estimator, and it's worth budgeting for given the tank-to-injector leak path above.

Carbon buildup is a standard direct-injection wear item on this engine like any other: no fuel washes the backs of the intake valves, so deposits build over time and can eventually show up as rough idle or misfire codes. No F90-specific mileage threshold turned up in owner writeups, so treat it as a "someday" line item rather than a scheduled service. The same reasoning applies to the PCV system: it's a closed-loop design recirculating crankcase vapor back into the intake, and the aftermarket catch-can market that's grown up around this engine exists mostly to slow carbon buildup down, not eliminate a known failure.

One 2021 M5 complaint in CarScout's NHTSA-sourced data involved a reported fire, with no crash or injury attached. It's a single filing, not a pattern, but worth a mention alongside the fuel system items above.

M5 Competition and M5 CS: What the Extra Power Actually Costs

The Competition's extra 17 hp comes from an ECU retune, not new hardware, so a Competition carries the exact same coolant tank and injector risk profile as a base M5. What you're really paying for is the stiffer springs and dampers and the visual differentiation, which matter more on a track day than a commute.

The M5 CS is a different animal in the used market, mostly because so few exist. BMW built it for the 2022 model year only, and CarScout's own trim-group data shows roughly 15 active CS listings nationwide against 262 for the standard M5/Competition group combined. That scarcity cuts both ways: CS values have held up well, but parts availability and body shop familiarity with its carbon panels are both thinner than for a standard car. Standard carbon-ceramic brakes are a genuine functional upgrade for anyone who tracks the car, and a real cost trap for anyone who doesn't: they're spectacular under repeated hard stops and expensive to replace if they've been cooked by a previous owner who used them as daily street brakes.

M xDrive AWD: The One Constant

Every F90 M5 sold in the US came standard with M xDrive, confirmed across every model year's EPA filing. A pre-production RWD-only prototype was tested during development but never reached a US showroom, so don't go looking for a "true rear-drive" F90 in the classifieds; it doesn't exist here. The system does let the driver dial toward a rear-biased or full 2WD mode through the M Drive settings, which is where the RWD driving character people mention on forums comes from, not from different hardware. No widespread transfer-case failure pattern turned up for this generation specifically, but budget for periodic transfer case fluid service as one more line item alongside the V8.

Trim Levels

The Competition Package's chassis changes matter more once you're pushing the car near its limits than they do in daily driving; a well-kept base M5 gives up little on the road most people actually drive. The 2021 refresh is worth cross-shopping for regardless of trim: it brought updated tech that pre-facelift cars simply don't have, and it lines up with the model year every recall on this generation had already stopped by.

Wheel size and style track model year more than trim: 20-inch forged wheels are standard across the range, and staggered widths front to rear mean tire replacement always means buying two different sizes, not a matching set of four. That matters for the running-cost math below. The Executive Package, where fitted, adds features like a heads-up display and soft-close doors; it's a nice-to-have that tells you a car was optioned by an owner who spent freely, but it doesn't change anything about the mechanical checklist. Carbon-ceramic brakes were a standalone option on the M5 and Competition before becoming standard on the CS, and the same warning applies regardless of trim: they're excellent under real track abuse and a liability on a street car whose seller used them hard without saying so.

Which Model Years to Target Within This Generation

Every recall on this generation landed in its first two model years and none have applied since, which makes 2021 the clean break point. The 2018 M5 carries two: campaign 18V323000, where engine control software could stop the fuel pump and stall the car, and 18V473000, where the fuel level sensor could jam against a fuel line and read inaccurately. The 2019 M5 carries campaign 19V883000, a transmission wiring harness that could short and drop the car into neutral, which BMW's own filing also names as covering 2020 M5 production, plus campaign 19V513000, the high-pressure fuel pump fire-risk recall covered above.

If you want the extra power and standard carbon-ceramic brakes, 2022 is the only model year the CS existed, and it comes with the best overall complaint record of the generation. If you'd rather bank the savings, a 2021 or 2023 Competition delivers nearly identical performance with far more used supply than the CS will ever have.

The complaint counts back up the recall pattern. In CarScout's NHTSA-sourced data, the 2018 M5 logged 4 complaints and the 2019 logged 8, the two highest totals in the generation and the two years carrying every recall. From 2020 on, complaint volume drops to 1 or 2 filings a year. Read that as directional, not definitive: complaint counts track how many of each model year sold and how long they've been on the road, not just how reliable they turned out to be. A 2018 or 2019 car isn't a bad buy on its own; it's a car where the recall paperwork and injector history need to actually check out before you pay.

Pre-Purchase Inspection Checklist

• Pop the hood cold and inspect the coolant expansion tank first. Look for dried coolant crust, a swollen or previously replaced cap, or any residue on the fuel injectors mounted just below it. This is the single most common ownership surprise on this generation, and it's a two-minute check.
• Ask directly whether the car has ever had a coolant leak reach the fuel injectors. If the seller doesn't know, ask for service records covering coolant top-offs, since a slow leak often shows up there before anyone notices a puddle.
• Have a shop scan for stored misfire or fuel trim codes that might point to injector wear from fuel dilution, and pull an oil sample or filter cut if the car is past 60,000 miles to check for bearing glitter.
• Run the VIN through a recall lookup and confirm 18V323000 and 18V473000 show complete on a 2018 car, and that 19V883000 and 19V513000 show complete on a 2019 or 2020 car.
• Ask whether the ECU has ever been flashed. Tunes are common on this platform and push more fuel and boost through the same injectors and fuel pump, raising the risk of the failures above. A tune history isn't disqualifying, but it changes what you should budget for.
• Check tire and brake wear closely. A full set of performance tires runs $1,100 to $1,400 and a brake job $1,200 to $1,800 per axle; a neglected example will need both soon after you buy it.
• On an M5 CS, inspect the carbon-ceramic brakes for glazing or overheating from track use, since replacement costs far more than the steel brakes on a standard M5 or Competition.
• Check both front and rear tire sizes match a legitimate staggered set. The F90 runs different widths front and rear; mismatched or mixed-brand tires are a sign of a seller replacing only what wore out, not the full set.
• Ask when the transfer case fluid was last serviced. M xDrive is standard on every F90, and while no widespread failure pattern turned up for this generation, it's a maintenance item that gets skipped more often than the engine oil.

Running Costs

Every F90 trim requires premium fuel and returns the same 17 mpg combined per EPA testing, which runs roughly $4,800 a year at EPA's assumed mileage. Insurance averages around $5,170 a year according to cost-of-ownership research, well above a standard 5 Series given the performance rating. Oil changes are the one routine service that's cheap to defer and expensive to skip: BMW's computer interval can stretch past 10,000 miles, but specialist shops and the wider M community both push back on that on a turbocharged engine this highly strung, and most independent BMW shops recommend 5,000 to 7,500-mile intervals instead, running $150 to $250 a visit.

The real ownership math shows up once the factory warranty lapses: tires, brakes, and the coolant tank and injector chain above are the recurring costs that separate a well-kept F90 from a neglected one, and they stack quickly on a car this powerful. Budget a real annual repair reserve rather than assuming the EPA and insurance numbers above are the whole picture; the difference between a documented car and an undocumented one is routinely several thousand dollars of deferred work that won't show up in a set of listing photos.

FAQ

Is the BMW M5 F90 reliable? Yes, by high-performance sedan standards, though it isn't maintenance-free. The S63TU V8 doesn't carry the rod bearing reputation of older M engines, but the plastic coolant expansion tank is a documented weak point that can leak onto the fuel injectors below it. A well-maintained example with documented coolant and injector history is a safe buy.

What year F90 M5 should I avoid? None outright, but 2018 and 2019 carry every recall this generation has: two on the 2018 (fuel pump software, fuel sensor) and two more tied to 2019 production (transmission harness, high-pressure fuel pump). Confirm all four show complete before buying either year, or budget accordingly if they don't.

Does the F90 M5 have rod bearing problems like older M5s? Not in the same way. Forum and technical consensus on the S63TU points to leaky fuel injectors diluting engine oil as the real driver of bearing wear, not age or mileage alone. That means the fuel system, not the bearings themselves, is what to screen for on a used F90.

Is the BMW M5 Competition worth the extra money over the base M5? Mechanically they're identical risks, since the Competition's extra 17 hp comes from a software retune, not new parts. The Competition's stiffer suspension tuning matters most if you plan to drive the car hard; for daily use, a well-kept base M5 gives up very little.

How many miles will an F90 M5 last? Owners on BimmerPost and M5board.com regularly report six-figure mileage with no major engine work, provided the coolant tank and fuel injectors have been kept ahead of rather than ignored. The car that fails early is almost always the one where a slow coolant leak went unnoticed, not one that simply wore out.

The Bottom Line

The F90 M5 is the value play in used M5 shopping right now: real supercar-embarrassing performance, a back seat that works, and a mechanical story that's far less scary than the M cars that came before it, provided you screen for one specific part. It's also a car built to be driven hard and daily at the same time, which is exactly why used examples show up with such a wide spread of condition and honesty. Check the coolant expansion tank and ask about injector history before anything else. A 2021 or later Competition gets you the facelift's updated tech and a clean recall record without CS money. Run every VIN through a recall check first. CarScout members can set alerts on specific F90 model years and trims to catch documented cars when they list at usecarscout.com.

Data sourced from NHTSA recalls database, EPA fuel economy data, and real owner experiences from BimmerPost's F90 M5 forum (f90.bimmerpost.com) and M5board.com's F90 discussion section. See the full BMW M5 market data for pricing and inventory.