2018 Hyundai Ioniq — Full Specifications
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The 2018 Hyundai Ioniq is a hatchback powered by a 1.6L 4-cyl regular gasoline engine. Its most fuel-efficient configuration returns around 70 mpg (UK) / 58 mpg (US EPA) combined, with 62–70 mpg (UK) across all configurations. Owners often keep a Hyundai Ioniq workshop manual to hand for servicing and repairs.
Compared with the 2017 Hyundai Ioniq: Fuel economy improves from 66 to 70 mpg (UK) combined on the most efficient configuration. The engine line-up listed by EPA is unchanged.
Full Specifications
| Engine | 1.6L 4-cyl |
|---|---|
| Transmission | Automatic (AM6) |
| Fuel Type | Regular Gasoline |
| Powertrain | Hybrid |
| Drive | Front-Wheel Drive |
| Body Style | Hatchback |
| Passenger Volume (EPA) | 96 cu ft (2,718 L) |
| Luggage Volume (EPA) | 27 cu ft (765 L) |
| Fuel Economy (UK) | 70 combined / 68 urban / 71 extra-urban mpg |
| Fuel Economy (US EPA) | 58 combined / 57 city / 59 highway mpg |
| CO₂ Emissions | 96 g/km |
| EPA Greenhouse Gas Score | 10 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $1,150 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2018 Hyundai Ioniq, all with the 1.6L 4-cyl engine. Combined fuel economy ranges from 52 to 58 mpg (US), or 62 to 70 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 |
|---|---|---|---|---|---|---|
| 1.6L 4-cyl (Hybrid) | Automatic (AM6) | Front-Wheel Drive | 70 | 58 (57/59) | 96 | $1,150 |
| 1.6L 4-cyl (Plug-in Hybrid) | Automatic (AM6) | Front-Wheel Drive | 62 | 52 (53/52) | 47 | $1,300 |
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 27 cubic feet (about 765 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 Hyundai Ioniq
Running Costs: 2018 Hyundai Ioniq
Covering around 8,000 miles a year in a 2018 Hyundai Ioniq at 70 mpg combined, expect roughly 520 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $1,150 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 Hyundai Ioniq Safety Ratings (NHTSA)
No NHTSA crash-test rating is on record for this model year. The NHTSA rates only a subset of vehicles each year; you can browse every rated vehicle on our NHTSA Safety Ratings hub.
Recalls & Owner Complaints (NHTSA)
NHTSA lists 2 safety recall campaigns that include the 2018 Hyundai Ioniq (as of 6 October 2026). Most affected areas: Hybrid propulsion system (2). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Hybrid propulsion system — campaign 22V459000, reported 28 June 2022. Risk: An overheated PRA increases the risk of a fire.
- Hybrid propulsion system — campaign 18V704000, reported 5 October 2018. Risk: The increased electrical resistance can overheat the rear seat which is above the PRA, increasing the risk of a fire.
Owners have filed 17 complaints with NHTSA about the 2018 Hyundai Ioniq. The most-reported areas are Unspecified (4), Engine (3), Power train (3). Complaints include 2 reported crashes, 2 reported injuries. That is well below the median of 31 complaints across the 6 Hyundai Ioniq model years in our data.
Used-buyer checklist for the 2018 Hyundai Ioniq
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Engine (3 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
- Transmission & drivetrain (3 owner complaints) — On the test drive, watch for hesitation, jerking or slipping between gears and ask for transmission service history.
- 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
Hyundai models in our database average about 34 mpg (UK) combined on their most efficient configuration; the 2018 Hyundai Ioniq's 70 mpg is 36 mpg above that make average. Its 96 g/km CO₂ figure is 111 g/km lower than the 207 g/km Hyundai average.
Of the 6 Hyundai Ioniq model years we cover, the 2018 is the most economical on its best configuration (70 mpg UK combined). See every Hyundai Ioniq 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 Hyundai Ioniq
Frequently Asked Questions
What engine does the 2018 Hyundai Ioniq have?
It's fitted with a 1.6L 4-cyl regular gasoline engine, paired with a automatic (am6) transmission.
What is the fuel economy of the 2018 Hyundai Ioniq?
The most efficient configuration returns around 70 mpg (UK) combined, or 58 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 62 to 70 mpg.
How much does the 2018 Hyundai Ioniq cost to fuel per year?
The US EPA estimates about $1,150 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 Hyundai Ioniq have any recalls?
NHTSA lists 2 safety recall campaigns that include the 2018 Hyundai Ioniq (as of 6 October 2026). Most affected areas: Hybrid propulsion system (2). 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 Hyundai Ioniq?
Among the 17 owner complaints filed with NHTSA, the most-reported areas are Unspecified (4 complaints), Engine (3 complaints), Power train (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 2018 Hyundai Ioniq have?
EPA measures interior passenger volume at 96 cubic feet (about 2,718 litres) and luggage volume at 27 cubic feet (about 765 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.