2021 Ford Mustang Convertible — Full Specifications
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The 2021 Ford Mustang Convertible is a coupe offered with 2 engines (2.3L 4-cyl turbo, 5L 8-cyl). Its most fuel-efficient configuration returns around 28 mpg (UK) / 23 mpg (US EPA) combined, with 22–28 mpg (UK) across all configurations. Owners often keep a Ford Mustang Convertible workshop manual to hand for servicing and repairs.
Related listing: see also the 2021 Ford Mustang page for the base Mustang listing, which may cover additional engines and body styles.
Compared with the 2020 Ford Mustang Convertible: Fuel economy is essentially unchanged at around 28 mpg (UK) combined. The engine line-up listed by EPA is unchanged. It carries the same 5★ overall NHTSA rating.
Full Specifications
| Engine (most efficient) | 2.3L 4-cyl turbo |
|---|---|
| Engine options | 2.3L 4-cyl turbo · 5L 8-cyl |
| Transmission (most efficient) | Automatic (S10) |
| Fuel Type | Regular Gasoline |
| Powertrain | Conventional |
| Drive | Rear-Wheel Drive |
| Body Style | Coupe |
| Passenger Volume (EPA) | 80 cu ft (2,265 L) |
| Luggage Volume (EPA) | 11 cu ft (311 L) |
| Fuel Economy (UK) | 28 combined / 24 urban / 34 extra-urban mpg |
| Fuel Economy (US EPA) | 23 combined / 20 city / 28 highway mpg |
| CO₂ Emissions | 240 g/km |
| EPA Greenhouse Gas Score | 5 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $2,900 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 4 configurations for the 2021 Ford Mustang Convertible across 2 engines (2.3L 4-cyl turbo, 5L 8-cyl). Combined fuel economy ranges from 18 to 23 mpg (US), or 22 to 28 mpg (UK), depending on engine, transmission and drive. The headline figures at the top of this page describe the most fuel-efficient configuration.
| Engine | Transmission | Drive | MPG (UK) | MPG (US) | CO₂ g/km | Fuel cost / yr |
|---|---|---|---|---|---|---|
| 2.3L 4-cyl turbo | Automatic (S10) | Rear-Wheel Drive | 28 | 23 (20/28) | 240 | $2,900 |
| 2.3L 4-cyl turbo | Automatic 10-spd | Rear-Wheel Drive | 28 | 23 (20/28) | 240 | $2,900 |
| 2.3L 4-cyl turbo | Manual 6-spd | Rear-Wheel Drive | 28 | 23 (20/27) | 240 | $2,900 |
| 5L 8-cyl | Automatic (S10) | Rear-Wheel Drive | 22 | 18 (15/23) | 306 | $3,700 |
MPG (US) shows combined, with city/highway in brackets. Highlighted row = the configuration used for the headline figures. Source: US EPA fueleconomy.gov.
EPA measures interior passenger volume at 80 cubic feet (about 2,265 litres) and luggage volume at 11 cubic feet (about 311 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2021 Ford Mustang Convertible
Running Costs: 2021 Ford Mustang Convertible
Covering around 8,000 miles a year in a 2021 Ford Mustang Convertible at 28 mpg combined, expect roughly 1,299 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $2,900 a year in fuel for the most efficient configuration (15,000 miles, national average prices). Work out exact fuel costs with the fuel cost calculator on 247Calculators.
Convert between MPG and L/100km with the unit converters on 247QuickTools. Not sure what tyre size fits? 247TyreCheck explains tyre sizing.
Only need this car occasionally? See our buy vs rent comparison.
2021 Ford Mustang Convertible Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 6 safety recall campaigns that include the 2021 Ford Mustang Convertible (as of 6 October 2026). Most affected areas: Electrical system (2), Air bags (2), Fuel system (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Electrical system — campaign 25V689000, reported 10 October 2025. Risk: Without a low brake fluid warning light, the vehicle may be driven with low brake fluid, reducing braking performance and increasing the risk of a crash.
- Fuel system — campaign 25V455000, reported 7 July 2025. Risk: An engine stall increases the risk of a crash.
- Back over prevention — campaign 25V442000, reported 27 June 2025. Risk: A rearview camera that displays a blank image can reduce the driver's view behind the vehicle. A rearview image that continues to be displayed after the vehicle is shifted out of reverse may distract the…
- Electrical system — campaign 23V727000, reported 27 October 2023. Risk: Without a low brake fluid warning light, the vehicle may be driven with low brake fluid, reducing braking performance and increasing the risk of a crash.
Showing the 4 most recent of 6 campaigns.
Owners have filed 55 complaints with NHTSA about the 2021 Ford Mustang Convertible. The most-reported areas are Fuel system (10), Power train (9), Engine (8). Complaints include 4 reported crashes, 2 reported injuries. That is well below the median of 265 complaints across the 13 Ford Mustang Convertible model years in our data.
Used-buyer checklist for the 2021 Ford Mustang Convertible
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Electrical system (2 recall campaigns · 6 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Fuel system (1 recall campaign · 10 owner complaints) — Ask whether any fuel-pump or fuel-system recalls were completed, and watch for hard starting or stalling.
- Air bags (2 recall campaigns) — Confirm any air bag inflator or module recalls were completed — enter the VIN at nhtsa.gov/recalls.
- Transmission & drivetrain (9 owner complaints) — On the test drive, watch for hesitation, jerking or slipping between gears and ask for transmission service history.
Source: US NHTSA recall and consumer-complaint databases, retrieved 6 October 2026. Complaints are unverified owner reports, not confirmed defects. Check any vehicle by VIN at nhtsa.gov/recalls, and see our guide to checking a used car for recalls.
How It Compares
How does the Ford Mustang Convertible compare to similar coupes? For context, coupes in our database average around 25 mpg (UK) combined — this model's 28 mpg figure is 3 mpg better than that average. Its 240 g/km CO₂ figure is 38 g/km lower than the 278 g/km average for coupes on this site. This comparison is based on 1072 coupes in our dataset.
At 28 mpg (UK) combined it sits close to the 28 mpg average for Ford models in our database. Its 240 g/km CO₂ figure is 15 g/km lower than the 255 g/km Ford average.
Of the 13 Ford Mustang Convertible model years we cover, the 2021 ranks 2nd for combined fuel economy on its best configuration (28 mpg UK combined, against a high of 29 mpg). See every Ford Mustang Convertible year side by side.
Last updated: · Data: US EPA (fueleconomy.gov) and NHTSA safety ratings 18 July 2026; NHTSA recalls and complaints 6 October 2026; Wikidata & curated EU catalogue 18 July 2026; European generation and engine data from Wikipedia 7 October 2026
Vehicle data sourced from manufacturer specifications. Always verify with your vehicle handbook or a qualified mechanic. This is a reference tool, not professional advice.
Recommended Accessories for the 2021 Ford Mustang Convertible
Frequently Asked Questions
What engine does the 2021 Ford Mustang Convertible have?
EPA lists 2 engines for the 2021 Ford Mustang Convertible: 2.3L 4-cyl turbo, 5L 8-cyl. The most fuel-efficient configuration pairs the 2.3L 4-cyl turbo with a automatic (s10).
What is the fuel economy of the 2021 Ford Mustang Convertible?
The most efficient configuration returns around 28 mpg (UK) combined, or 23 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 22 to 28 mpg.
How much does the 2021 Ford Mustang Convertible cost to fuel per year?
The US EPA estimates about $2,900 a year in fuel for the most efficient configuration, based on 15,000 miles of mixed driving and national average fuel prices. Your own cost will depend on mileage and local prices.
Does the 2021 Ford Mustang Convertible have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 5 stars for frontal crash protection.
Does the 2021 Ford Mustang Convertible have any recalls?
NHTSA lists 6 safety recall campaigns that include the 2021 Ford Mustang Convertible (as of 6 October 2026). Most affected areas: Electrical system (2), Air bags (2), Fuel system (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
What are the most common problems reported for the 2021 Ford Mustang Convertible?
Among the 55 owner complaints filed with NHTSA, the most-reported areas are Fuel system (10 complaints), Power train (9 complaints), Engine (8 complaints). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
How much interior and luggage space does the 2021 Ford Mustang Convertible have?
EPA measures interior passenger volume at 80 cubic feet (about 2,265 litres) and luggage volume at 11 cubic feet (about 311 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.
Is the Ford Mustang Convertible's fuel economy good for a coupe?
Yes — it returns around 28 mpg (UK) combined, against a same-body-style average of roughly 25 mpg among the coupes we track, making it one of the more efficient options in its class.