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BMW M340IModel year report

2021 BMW M340I Problems

Complaints
11filed with NHTSA
Median mileage
4,000miles, 1 complaints with mileage
Recalls
6campaigns on record
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA crash rating
—no overall rating published
EPA fuel economy
26 mpgcombined, 3.0L 6-cyl · hybrid RWD · 23 city / 32 hwy

Sources: NHTSA records for the 2021 BMW M340I (complaints, recalls, investigations), EPA fuel economy. Report an error

NHTSA recorded 11 consumer complaints for the 2021 BMW M340I. The part named most often is engine, with 7 complaints (64% of the total), followed by transmission and drivetrain (3) and electrical system (2). 1 of the complaints include a mileage, and 100% of those were filed for vehicles with under 50,000 miles; the median is 4,000 miles. NHTSA lists 6 recall campaigns and 183 technical service bulletins for this model year. Engine complaints overlap with 7 technical service bulletins filed under the same part. Transmission and drivetrain complaints overlap with 7 technical service bulletins filed under the same part.

This model year has fewer than 25 complaints on record, so the numbers below can change a lot with a few new reports.

Which parts are reported most

Complaints can name more than one part, so the counts add up to more than the total. Select a part to see its complaints, recalls and bulletins.

Example complaints

Engine: “I have been smelling a burning odor in the vehicle for almost a year which the dealership and an independent shop had not been able to diagnose. The car was recently throwing Drivetrain Error codes which prompted a visit to the dealership. They found that the 48v battery and negative cable are burnt and quoted $5680 to replace the battery and cables. After investigating I found that there were recalls for this issue on other BMWs, including the same year and model of my vehicle, but my VIN is not pulling up a recall. …”

NHTSA complaint #11747887, filed 2026-07

Transmission and drivetrain: “Here’s a strong version that sounds frustrated but still credible and harder to dismiss: I’ve owned many vehicles over the years, and this BMW has been, without question, the most problematic car I’ve ever had. The list of issues has been absurd for a vehicle in this price range and from a brand that markets itself as a premium luxury manufacturer. …”

NHTSA complaint #11738468, filed 2026-05

Brakes: “The contact owns a 2021 BMW M340I. The contact stated while driving various speeds, the vehicle independently shifted from reverse(R) to drive(D) to park(P). The contact stated that while driving approximately 10 MPH and attempting to stop the vehicle, the brake pedal was depressed and went to the floorboard. The contact stated that the brake failed to operate as designed. The vehicle was towed to a dealer who diagnosed that the vacuum pump needed to be replaced. The vehicle was repaired. The contact stated that an unknown transmission repair was performed. …”

NHTSA complaint #11491782, filed 2022-11, 4,000 miles

Mileage when problems were reported

100% of the 1 complaints with a mileage were filed for vehicles with under 50,000 miles; the middle half falls between 4,000 and 4,000 miles.

100%0–100%10–250%25–500%50–750%75–1000%100–1500%150+
Share of complaints by mileage when the problem was reported, in thousands of miles (1 complaints with mileage). Red bars: under 50,000 miles. Bucket widths differ. Median: 4,000 miles.

Complaints by year filed

Fewer than 15 complaints, too few for a reliable trend.

20222023202520266
Complaints by year the complaint was filed with NHTSA. Red bars: the last 3 full calendar years used for the trend. The current year (2026) is partial.

Fuel economy and running cost

EPA ratings for each 2021 BMW M340I version. Annual fuel cost is the EPA's estimate at its current fuel prices for 15,000 miles a year (55% city driving).

VersionEngineTransmissionCityHwyComb.Fuel / yr
M340i RWD3.0L 6-cyl · hybrid8-speed automatic233226$3,150
M340i xDrive AWD3.0L 6-cyl · hybrid8-speed automatic223125$3,300

Source: U.S. EPA and Department of Energy, fueleconomy.gov. Ratings are for comparing vehicles; real-world mileage varies with driving and conditions.

Recalls and investigations

Recall details for the 2021 BMW M340I → · Check a VIN at nhtsa.gov/recalls

Technical service bulletins

TSBs are manufacturer notes to dealers about known repair procedures. They are not recalls and do not by themselves mean a vehicle has a fault. 183 on record; the latest 10 are shown.

See all 183 bulletins →

Other model years of the BMW M340I

YearComplaintsMedian miRecallsCrash ★MPGScore (50 = typical)Trend
202273001—26—Not enough data
2021114,0006—26—Not enough data
20205637,33110—25Not compared (fewer than 3 comparable model years)Rising

All BMW M340I model years

Frequently asked questions

How many NHTSA complaints does the 2021 BMW M340I have?

NHTSA recorded 11 consumer complaints for the 2021 BMW M340I as of Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

What part of the 2021 BMW M340I is reported most often?

Engine is named most often, in 7 complaints (64% of the total), followed by transmission and drivetrain with 3.

Has the 2021 BMW M340I been recalled?

NHTSA lists 6 recall campaigns for this model year. To check a specific vehicle, enter its VIN at nhtsa.gov/recalls.

What gas mileage does the 2021 BMW M340I get?

The EPA rates the 2021 BMW M340I (M340i, 3.0L 6-cyl · hybrid) at 26 mpg combined, 23 city and 32 highway, with an estimated annual fuel cost of $3,150 at 15,000 miles a year. Other engine and drive versions are rated differently.

At what mileage are problems with the 2021 BMW M340I reported?

Among the 1 complaints that include a mileage, the median is 4,000 miles and the middle half falls between 4,000 and 4,000 miles; 100% were filed for vehicles with under 50,000 miles.

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate. Fuel economy is from the EPA and DOE (fueleconomy.gov).

Complaint counts come from NHTSA’s public complaint database; we count each complaint once. The source records for this vehicle are on nhtsa.gov. Scores and trends are our own summaries of that data, described in the methodology. This page is not legal, safety or repair advice: for a specific vehicle, check its VIN at nhtsa.gov/recalls and ask a qualified mechanic. See an error? Tell us.