DecodedCars2021 BMW Z4
Trims, performance, features, fuel economy, safety and known problems — with the pros and cons against similar 2021 models.
- Class
- Two Seaters
- Body styles
- M40i 2dr Convertible, Sdrive30i 2dr Convertible
- Engines
- 2.0L 4-cyl turbo, 3.0L 6-cyl turbo
- Horsepower
- 255 hp
- Transmission
- 8-speed automatic
- Drivetrain
- Rear-Wheel Drive
- Seats
- 2
- Fuel
- Premium Gasoline
- MPG (best)
- 28 combined · 25 city / 32 hwy
- Length
- 170.9 in
- Curb weight
- 3,296–3,464 lb
- NHTSA rating
- Not rated
- Recalls
- 5 campaigns
Pros & cons
What's good
- Excellent fuel economyUp to 28 MPG combined — 47% better than the average 2021 two seaters (19.1 MPG).
Watch out for
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
- Modest powerUp to 255 hp, versus about 500 hp for similar 2021 models.
- "Park outside" recallCheck that the recall repair was done before buying or driving.
Calculated from EPA, NHTSA and vPIC data against 6 similar 2021 models — not a review. How we calculate this →
Overview
The 2021 BMW Z4 is a two seaters offered with 2 engines (2.0L 4-cyl turbo and 3.0L 6-cyl turbo) and rear-wheel drive.
It measures about 171 inches long and 73 inches wide on a 97-inch wheelbase, with a curb weight of roughly 3,464 lb (M40i 2dr Convertible).
EPA rates its most efficient version at 28 MPG combined (25 city / 32 highway), 47% better than the 2021 two seaters average of 19.1 MPG, for an estimated $2,950 a year in fuel.
NHTSA has not published a 5-Star overall rating for this model year.
It has 5 recall campaigns on file and owners have filed 1 complaint with NHTSA since 2015, most often about the unknown or other.
What changed for 2021
No changes to engines, powertrains, drivetrains, size, EPA ratings or NHTSA crash rating compared with the 2020 Z4 — a carry-over year in the data.
Compared with 2020; trim, feature and price changes aren't covered. See the 2020 Z4 →
Trims, performance & features
Trims
Safety & driver-assist features
Built in: Graz, Austria
NHTSA vPIC, as reported by the manufacturer for 1 2021 Z4 configuration; may not list every trim. How we calculate this →
Dimensions & weight
| Body | Length | Width | Height | Wheelbase | Track F / R | Curb weight | Weight F/R |
|---|---|---|---|---|---|---|---|
| M40i 2dr Convertible | 170.9 in | 73.2 in | 51.6 in | 97.2 in | 63.8 / 63.4 in | 3,464 lb | 51/49 |
| Sdrive30i 2dr Convertible | 170.9 in | 73.2 in | 51.6 in | 97.2 in | 63.8 / 63.4 in | 3,296 lb | 50/50 |
Transport Canada CVS (Open Government Licence – Canada), Canadian-market figures.
Will it fit your garage? Check with your measurements →Engines, MPG & running costs
| Version | Engine | Transmission | Drive | City / Hwy / Comb | vs. class | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|---|---|
| Z4 sDrive30i | 2.0L 4-cyl turbo | Automatic (S8) | Rear-Wheel Drive | 25 / 32 / 28 | +47% | $2,950 | 321 |
| Z4 M40i | 3.0L 6-cyl turbo | Automatic (S8) | Rear-Wheel Drive | 22 / 30 / 25 | +31% | $3,300 | 355 |
EPA estimates; "vs. class" is combined MPG against the 2021 EPA class average. How we calculate this →
Safety ratings & technology
NHTSA has not published 5-Star ratings for the 2021 BMW Z4.
Similar 2021 two seaterss
| Model | Best MPG / range | NHTSA overall | Recalls |
|---|---|---|---|
| 2021 BMW Z4 (this car) | 28 MPG | Not rated | 5 |
| 2021 Porsche 911 | 21 MPG | Not rated | 8 |
| 2021 Mercedes-Benz AMG GT | 22 MPG | Not rated | 12 |
| 2021 Acura NSX | 21 MPG | Not rated | 0 |
| 2021 Audi TT | 26 MPG | Not rated | 0 |
| 2021 Jaguar F-Type | 26 MPG | Not rated | 1 |
| 2021 Porsche 718 | 24 MPG | Not rated | 2 |
Recalls (5)
Electrical System › Starter Assembly · Jan 30, 2026
NHTSA campaign 26V056000 · 87,394 vehicles
- Problem
- BMW of North America, LLC (BMW) is recalling certain 2021-2023 Toyota Supra, 2022-2023 2 Series Coupe, 2021-2024 5 Series (xDrive), 2021-2022 Z4, 2022-2024 4 Series (Gran Coupe), 2021-2024 4 Series (Convertible and xDrive Convertible), 2021-2023 4 Series (Coupe), 2021-2024 3 Series, 2021-2023 X4, 2021-2024 X3 vehicles. Please see the recall report for a complete list of all models. The engine starter may overheat and catch fire due to wear on an internal component.
- Risk
- Fire increases the risk of injury.
- Fix
- Dealers will replace the engine starter, free of charge. Owner notification letters were mailed July 21, 2026. Owners may contact BMW customer service at 1-800-525-7417 or Toyota's customer service at 1-800-331-4331. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning March 24, 2026.
Electrical System › Starter Assembly › Relay · Sep 23, 2025 Park outside
NHTSA campaign 25V636000 · 199,674 vehicles
- Problem
- BMW of North America, LLC (BMW) is recalling certain 2019-2021 BMW 330i, 2019-2022 BMW Z4, 2020-2022 BMW 530i, X3, X4, Toyota Supra, 2021-2022 BMW 430i, 430i Convertible, and 2022 BMW 230i vehicles. The engine starter relay may corrode, causing the relay to overheat and short circuit.
- Risk
- A short circuit in the starter relay may increase the risk of a fire.
- Fix
- Owners are advised to park their vehicles outside and away from structures until the remedy is complete. Dealers will replace the engine starter, free of charge. Owner notification letters were mailed February 6, 2026. Owners may contact BMW customer service at 1-800-525-7417. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov November 14, 2025.
Engine · Aug 2, 2021
NHTSA campaign 21V598000 · 50,024 vehicles
- Problem
- BMW of North America, LLC (BMW) is recalling certain 2020 M340i, M340i xDrive, 540i, 540i xDrive, X3 M40i, 2020-2021 X4 M40i, 745Le xDrive, 2019-2021 Z4 M40i, and 2020-2021 Toyota Supra vehicles. During engine start, the engine management software may cause loss of braking assist. Full mechanical braking (without assist) remains available.
- Risk
- Loss of braking assist can increase the risk of a crash.
- Fix
- Dealers will update the engine management software, free of charge. Owner notification letters were mailed on September 17, 2021. Owners may contact BMW customer service at 1-800-525-7417.
Seat Belts · Jul 21, 2021
NHTSA campaign 21V554000 · 21,537 vehicles
- Problem
- BMW of North America, LLC (BMW) is recalling certain 2021 2 Series (230i, 230i xDrive, M240i, M240i xDrive), 330e, 330e Xdrive, 4 Series Coupe (430i, 430i xDrive, M440i xDrive) M4 Coupe, M4 Competition Coupe, BMW 4 Series Convertible (430i, M440i), BMW X1 sDrive28i, xDrive28i, 2 Series Gran Coupe (228i, 228i xDrive, M235i xDrive), M2 Competition Coupe, 330i, 330i xDrive, M340i, M340i xDrive, M3, M3 Competition, 530i, 530i xDrive, 540i, 540i xDrive, MINI Hardtop 2 Door (Cooper, CooperS, JCW), X2 sDrive28i, X2 xDrive28i, X2 M35i, Z4 sDrive30i, Z4 M40i, MINI Hardtop 2 Door (Cooper SE), MINI Convertible (Cooper, Cooper S, JCW), MINI Clubman (Cooper S, Cooper S All4, JCW), MINI Countryman (Cooper, Cooper All4, Cooper S, Cooper S All4, JCW All4), Rolls Royce Ghost, MINI Countryman (Cooper S E All4), Rolls Royce Phantom, Rolls Royce Cullinan, and Toyota Supra vehicles. The passenger seat belt Automatic Locking Retractor (ALR) may deactivate early, before the webbing fully retracts. As such, these assemblies fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."
- Risk
- During a crash, a seat belt retractor that does not function as intended increases the risk of injury.
- Fix
- Dealers will inspect the seat belt retractors (including the seat belts) and, if necessary, replace the retractors, free of charge. Owner notification letters were mailed on September 3, 2021. Owners may contact BMW customer service at 1-800-525-7417; 1-866-825-1525 (MINI); 1-877-877-3735 (Rolls Royce); and 1-888-270-9371 (Toyota).
Fuel System, Gasoline › Storage › Tank Assembly · Nov 12, 2020
NHTSA campaign 20V700000 · 49 vehicles
- Problem
- BMW of North America, LLC (BMW) is recalling certain 2020-2021 Z4 and 2020-2021 Toyota Supra vehicles. The weld between the fuel tank halves may have been insufficiently welded, causing the weld to fail.
- Risk
- The failed weld may allow fuel to leak, increasing the risk of a fire in the presence of an ignition source.
- Fix
- BMW will notify owners, and dealers will replace the fuel tank, free of charge. The recall began December 18, 2020. Owners may contact BMW customer service at 1-800-525-7417 or Toyota customer service at 1-888-270-9371.
Not every 2021 BMW Z4 is affected — only a VIN check confirms your car.
Owner-reported problems
Unverified owner reports; best-sellers collect more.
Used 2021 BMW Z4 buyer's checklist
- Run the VIN at nhtsa.gov/recalls. 5 recalls this year — ask for proof of repairs.
- Safety-critical recall. At least one recall carries a "Do Not Drive" or "Park Outside" warning. Do not buy until the VIN shows it was repaired.
- Before you pay: service records, a history report and an independent inspection.
Generated by DecodedCars from NHTSA recalls and owner complaints for the 2021 BMW Z4. Not a substitute for a professional inspection.
Other Z4 years
Compare all years →| Year | MPG (best) | Length | Overall | Recalls | Complaints |
|---|---|---|---|---|---|
| 2026 Z4 | 28 | 170.9 in | Not rated | 0 | 0 |
| 2025 Z4 | 28 | 170.9 in | Not rated | 0 | 1 |
| 2024 Z4 | 28 | 170.9 in | Not rated | 0 | 1 |
| 2023 Z4 | 28 | 170.9 in | Not rated | 2 | 0 |
| 2022 Z4 | 28 | 170.9 in | Not rated | 3 | 1 |
| 2020 Z4 | 27 | 170.9 in | Not rated | 6 | 5 |
| 2019 Z4 | 28 | 170.9 in | Not rated | 6 | 5 |
| 2016 Z4 | 26 | 166.9 in | Not rated | 1 | 4 |
| 2015 Z4 | 26 | 166.9 in | Not rated | 1 | 5 |
| 2014 Z4 | 26 | 166.9 in | Not rated | 3 | 7 |
| 2013 Z4 | 26 | 166.9 in | Not rated | 3 | 7 |
| 2012 Z4 | 27 | 166.9 in | Not rated | 4 | 5 |
Sources: EPA, NHTSA, Transport Canada, Wikimedia Commons. Not affiliated with NHTSA, the EPA or BMW. How we calculate this →