2018 Chevrolet Sonic — Full Specifications
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The 2018 Chevrolet Sonic is a saloon/sedan offered with 2 engines (1.4L 4-cyl turbo, 1.8L 4-cyl). Its most fuel-efficient configuration returns around 38 mpg (UK) / 32 mpg (US EPA) combined, with 34–38 mpg (UK) across all configurations. Owners often keep a Chevrolet Sonic workshop manual to hand for servicing and repairs.
Compared with the 2017 Chevrolet Sonic: Fuel economy is essentially unchanged at around 38 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) | 1.4L 4-cyl turbo |
|---|---|
| Engine options | 1.4L 4-cyl turbo · 1.8L 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) | 91 cu ft (2,577 L) |
| Luggage Volume (EPA) | 19 cu ft (538 L) |
| Fuel Economy (UK) | 38 combined / 34 urban / 44 extra-urban mpg |
| Fuel Economy (US EPA) | 32 combined / 28 city / 37 highway mpg |
| CO₂ Emissions | 174 g/km |
| EPA Greenhouse Gas Score | 7 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $2,100 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 4 configurations for the 2018 Chevrolet Sonic across 2 engines (1.4L 4-cyl turbo, 1.8L 4-cyl). Combined fuel economy ranges from 28 to 32 mpg (US), or 34 to 38 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 |
|---|---|---|---|---|---|---|
| 1.4L 4-cyl turbo | Automatic (S6) | Front-Wheel Drive | 36 | 30 (27/35) | 184 | $2,250 |
| 1.4L 4-cyl turbo | Manual 6-spd | Front-Wheel Drive | 38 | 32 (28/37) | 174 | $2,100 |
| 1.8L 4-cyl | Automatic (S6) | Front-Wheel Drive | 34 | 28 (25/34) | 193 | $2,400 |
| 1.8L 4-cyl | Manual 5-spd | Front-Wheel Drive | 35 | 29 (26/35) | 190 | $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 91 cubic feet (about 2,577 litres) and luggage volume at 19 cubic feet (about 538 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 Chevrolet Sonic
Running Costs: 2018 Chevrolet Sonic
Covering around 8,000 miles a year in a 2018 Chevrolet Sonic at 38 mpg combined, expect roughly 957 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $2,100 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 Chevrolet Sonic Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 1 safety recall campaign that include the 2018 Chevrolet Sonic (as of 6 October 2026). Most affected areas: Seats (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Seats — campaign 18V342000, reported 27 May 2018. Risk: In the event of a rear-impact crash, the seat-back may fail, increasing the risk of injury.
Owners have filed 14 complaints with NHTSA about the 2018 Chevrolet Sonic. The most-reported areas are Electrical system (5), Engine (4), Unspecified (2). That is well below the median of 48 complaints across the 9 Chevrolet Sonic model years in our data.
Used-buyer checklist for the 2018 Chevrolet Sonic
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Seats (1 recall campaign · 2 owner complaints) — Check seat adjusters, head restraints and seat-mounted sensors work, and confirm seat recalls were completed.
- Electrical system (5 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Engine (4 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
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
Chevrolet models in our database average about 29 mpg (UK) combined on their most efficient configuration; the 2018 Chevrolet Sonic's 38 mpg is 9 mpg above that make average. Its 174 g/km CO₂ figure is 72 g/km lower than the 246 g/km Chevrolet average.
Of the 9 Chevrolet Sonic model years we cover, the 2018 is the most economical on its best configuration (38 mpg UK combined). See every Chevrolet Sonic 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 Chevrolet Sonic
Frequently Asked Questions
What engine does the 2018 Chevrolet Sonic have?
EPA lists 2 engines for the 2018 Chevrolet Sonic: 1.4L 4-cyl turbo, 1.8L 4-cyl. The most fuel-efficient configuration pairs the 1.4L 4-cyl turbo with a manual 6-spd.
What is the fuel economy of the 2018 Chevrolet Sonic?
The most efficient configuration returns around 38 mpg (UK) combined, or 32 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 34 to 38 mpg.
How much does the 2018 Chevrolet Sonic cost to fuel per year?
The US EPA estimates about $2,100 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 Chevrolet Sonic have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 5 stars for frontal crash protection.
Does the 2018 Chevrolet Sonic have any recalls?
NHTSA lists 1 safety recall campaign that include the 2018 Chevrolet Sonic (as of 6 October 2026). Most affected areas: Seats (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 Chevrolet Sonic?
Among the 14 owner complaints filed with NHTSA, the most-reported areas are Electrical system (5 complaints), Engine (4 complaints), Unspecified (2 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 Chevrolet Sonic have?
EPA measures interior passenger volume at 91 cubic feet (about 2,577 litres) and luggage volume at 19 cubic feet (about 538 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.