2020 Mazda 3 4-Door — Full Specifications
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The 2020 Mazda 3 4-Door is a saloon/sedan powered by a 2.5L 4-cyl regular gasoline engine. Its most fuel-efficient configuration returns around 36 mpg (UK) / 30 mpg (US EPA) combined, with 34–36 mpg (UK) across all configurations. Owners often keep a Mazda 3 4-Door workshop manual to hand for servicing and repairs.
Related listing: see also the 2020 Mazda 3 page for the base 3 listing, which may cover additional engines and body styles.
Compared with the 2019 Mazda 3 4-Door: Fuel economy is essentially unchanged at around 36 mpg (UK) combined. The engine line-up listed by EPA is unchanged. It holds a 5★ overall NHTSA rating (none is on record for the 2019 model).
Full Specifications
| Engine | 2.5L 4-cyl |
|---|---|
| Transmission | Automatic (S6) |
| Fuel Type | Regular Gasoline |
| Powertrain | Conventional |
| Drive | Front-Wheel Drive |
| Body Style | Saloon/Sedan |
| Passenger Volume (EPA) | 93 cu ft (2,633 L) |
| Luggage Volume (EPA) | 13 cu ft (368 L) |
| Fuel Economy (UK) | 36 combined / 31 urban / 42 extra-urban mpg |
| Fuel Economy (US EPA) | 30 combined / 26 city / 35 highway mpg |
| CO₂ Emissions | 186 g/km |
| EPA Greenhouse Gas Score | 7 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $2,250 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2020 Mazda 3 4-Door, all with the 2.5L 4-cyl engine. Combined fuel economy ranges from 28 to 30 mpg (US), or 34 to 36 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 |
|---|---|---|---|---|---|---|
| 2.5L 4-cyl | Automatic (S6) | 4-Wheel Drive | 34 | 28 (25/33) | 194 | $2,400 |
| 2.5L 4-cyl | Automatic (S6) | Front-Wheel Drive | 36 | 30 (26/35) | 186 | $2,250 |
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 93 cubic feet (about 2,633 litres) and luggage volume at 13 cubic feet (about 368 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2020 Mazda 3 4-Door
Running Costs: 2020 Mazda 3 4-Door
Covering around 8,000 miles a year in a 2020 Mazda 3 4-Door at 36 mpg combined, expect roughly 1,010 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $2,250 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.
2020 Mazda 3 4-Door Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 2 safety recall campaigns that include the 2020 Mazda 3 4-Door (as of 6 October 2026). Most affected areas: Service brakes (1), Forward collision avoidance (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Service brakes — campaign 20V346000, reported 12 June 2020. Risk: Loose brake calipers can reduce braking performance or interfere with wheel rotation, affecting vehicle handling. Either of these scenarios can increase the risk of a crash.
- Forward collision avoidance — campaign 19V907000, reported 19 December 2019. Risk: Stopping the vehicle unexpectedly increases the risk of a crash.
Owners have filed 32 complaints with NHTSA about the 2020 Mazda 3 4-Door. The most-reported areas are Forward collision avoidance (15), Steering (3), Electrical system (3). That is well below the median of 74 complaints across the 11 Mazda 3 4-Door model years in our data.
Used-buyer checklist for the 2020 Mazda 3 4-Door
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Driver-assist sensors (1 recall campaign · 15 owner complaints) — Check that driver-assist warning lights are off and sensors are clean and undamaged.
- Brakes (1 recall campaign) — Brake firmly from speed and look for pulling, vibration or a soft pedal; ask for brake service history.
- Steering (3 owner complaints) — Check for play, noise or heavy steering, and ask whether any steering recall work was done.
- Electrical system (3 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
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
Mazda models in our database average about 34 mpg (UK) combined on their most efficient configuration; the 2020 Mazda 3 4-Door's 36 mpg is 2 mpg above that make average. Its 186 g/km CO₂ figure is 12 g/km lower than the 198 g/km Mazda average.
Of the 13 Mazda 3 4-Door model years we cover, the 2020 ranks 11th for combined fuel economy on its best configuration (36 mpg UK combined, against a high of 40 mpg). See every Mazda 3 4-Door 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 2020 Mazda 3 4-Door
Frequently Asked Questions
What engine does the 2020 Mazda 3 4-Door have?
It's fitted with a 2.5L 4-cyl regular gasoline engine, paired with a automatic (s6) transmission.
What is the fuel economy of the 2020 Mazda 3 4-Door?
The most efficient configuration returns around 36 mpg (UK) combined, or 30 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 34 to 36 mpg.
How much does the 2020 Mazda 3 4-Door cost to fuel per year?
The US EPA estimates about $2,250 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 2020 Mazda 3 4-Door have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 5 stars for frontal crash protection.
Does the 2020 Mazda 3 4-Door have any recalls?
NHTSA lists 2 safety recall campaigns that include the 2020 Mazda 3 4-Door (as of 6 October 2026). Most affected areas: Service brakes (1), Forward collision avoidance (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 2020 Mazda 3 4-Door?
Among the 32 owner complaints filed with NHTSA, the most-reported areas are Forward collision avoidance (15 complaints), Steering (3 complaints), Electrical system (3 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 2020 Mazda 3 4-Door have?
EPA measures interior passenger volume at 93 cubic feet (about 2,633 litres) and luggage volume at 13 cubic feet (about 368 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.