2018 Mazda 3 4-Door — Full Specifications
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The 2018 Mazda 3 4-Door is a saloon/sedan offered with 2 engines (2L 4-cyl, 2.5L 4-cyl). Its most fuel-efficient configuration returns around 37 mpg (UK) / 31 mpg (US EPA) combined, with 35–37 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 2018 Mazda 3 page for the base 3 listing, which may cover additional engines and body styles.
Compared with the 2017 Mazda 3 4-Door: Fuel economy is essentially unchanged at around 37 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) | 2L 4-cyl |
|---|---|
| Engine options | 2L 4-cyl · 2.5L 4-cyl |
| Transmission (most efficient) | Manual 6-spd |
| Fuel Type | Regular Gasoline |
| Powertrain | Conventional |
| Drive | Front-Wheel Drive |
| Body Style | Saloon/Sedan |
| Passenger Volume (EPA) | 96 cu ft (2,718 L) |
| Luggage Volume (EPA) | 12 cu ft (340 L) |
| Fuel Economy (UK) | 37 combined / 34 urban / 46 extra-urban mpg |
| Fuel Economy (US EPA) | 31 combined / 28 city / 38 highway mpg |
| CO₂ Emissions | 175 g/km |
| EPA Greenhouse Gas Score | 7 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $2,150 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 4 configurations for the 2018 Mazda 3 4-Door across 2 engines (2L 4-cyl, 2.5L 4-cyl). Combined fuel economy ranges from 29 to 31 mpg (US), or 35 to 37 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 |
|---|---|---|---|---|---|---|
| 2L 4-cyl | Automatic (S6) | Front-Wheel Drive | 37 | 31 (28/37) | 176 | $2,150 |
| 2L 4-cyl | Manual 6-spd | Front-Wheel Drive | 37 | 31 (28/38) | 175 | $2,150 |
| 2.5L 4-cyl | Automatic (S6) | Front-Wheel Drive | 36 | 30 (27/36) | 182 | $2,250 |
| 2.5L 4-cyl | Manual 6-spd | Front-Wheel Drive | 35 | 29 (25/34) | 194 | $2,300 |
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 96 cubic feet (about 2,718 litres) and luggage volume at 12 cubic feet (about 340 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2018 Mazda 3 4-Door
Running Costs: 2018 Mazda 3 4-Door
Covering around 8,000 miles a year in a 2018 Mazda 3 4-Door at 37 mpg combined, expect roughly 983 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $2,150 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.
2018 Mazda 3 4-Door Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 4 safety recall campaigns that include the 2018 Mazda 3 4-Door (as of 6 October 2026). Most affected areas: Back over prevention (1), Fuel system (1), Visibility (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Back over prevention — campaign 23V487000, reported 14 July 2023. Risk: A rearview camera that does not display properly can reduce the driver's rear view, increasing the risk of a crash or injury.
- Fuel system — campaign 21V875000, reported 12 November 2021. Risk: Fuel pump failure may cause an engine stall, increasing the risk of a crash.
- Visibility — campaign 19V272000, reported 4 April 2019. Risk: Reduced visibility while driving can increase the risk of crash.
- Engine and engine cooling — campaign 17V745000, reported 21 November 2017. Risk: An engine stall can increase the risk of a crash.
Owners have filed 108 complaints with NHTSA about the 2018 Mazda 3 4-Door. The most-reported areas are Electrical system (30), Unspecified (26), Visibility/wiper (16). Complaints include 6 reported crashes, 5 reported injuries, 1 reported death. That is close to the median of 74 complaints across the 11 Mazda 3 4-Door model years in our data.
Used-buyer checklist for the 2018 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:
- Electrical system (30 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Visibility (1 recall campaign · 16 owner complaints) — Check wipers, washers and demisters work properly.
- Fuel system (1 recall campaign) — Ask whether any fuel-pump or fuel-system recalls were completed, and watch for hard starting or stalling.
- Engine cooling (1 recall campaign) — Check coolant level, look for leaks and make sure the temperature stays steady in traffic.
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 2018 Mazda 3 4-Door's 37 mpg is 3 mpg above that make average. Its 175 g/km CO₂ figure is 23 g/km lower than the 198 g/km Mazda average.
Of the 13 Mazda 3 4-Door model years we cover, the 2018 ranks 5th for combined fuel economy on its best configuration (37 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 2018 Mazda 3 4-Door
Frequently Asked Questions
What engine does the 2018 Mazda 3 4-Door have?
EPA lists 2 engines for the 2018 Mazda 3 4-Door: 2L 4-cyl, 2.5L 4-cyl. The most fuel-efficient configuration pairs the 2L 4-cyl with a manual 6-spd.
What is the fuel economy of the 2018 Mazda 3 4-Door?
The most efficient configuration returns around 37 mpg (UK) combined, or 31 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 35 to 37 mpg.
How much does the 2018 Mazda 3 4-Door cost to fuel per year?
The US EPA estimates about $2,150 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 2018 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 2018 Mazda 3 4-Door have any recalls?
NHTSA lists 4 safety recall campaigns that include the 2018 Mazda 3 4-Door (as of 6 October 2026). Most affected areas: Back over prevention (1), Fuel system (1), Visibility (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 2018 Mazda 3 4-Door?
Among the 108 owner complaints filed with NHTSA, the most-reported areas are Electrical system (30 complaints), Unspecified (26 complaints), Visibility/wiper (16 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 2018 Mazda 3 4-Door have?
EPA measures interior passenger volume at 96 cubic feet (about 2,718 litres) and luggage volume at 12 cubic feet (about 340 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.