The Chevrolet Onix does 22.5 mpg combined (20.3 city, 26.4 highway), which works out to about $1,707 a year in fuel at $3.20 a gallon and 12,000 miles. Engine choice matters more than you'd think: 2L 4-cyl does 24 mpg while 3.6L 6-cyl does 21 — a difference of $229 a year. Against other 4-cyl cars it sits below the average of 25.4 mpg.
Every Chevrolet Onix engine, compared
Picking the right version of the same car often saves more fuel than picking a different car altogether. Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 2L 4-cyl | 22 / 27 | 2021–2026 | $1,600 | |
| 3.6L 6-cyl | 18.5 / 25.8 | 2021–2026 | $1,829 |
What that actually costs
Miles per gallon is an abstraction; the fuel bill is not. Here it is in money, at 12,000 miles a year and $3.20 a gallon.
| Measure | Value |
|---|---|
| Cost per mile | $0.142 |
| Fuel per year | $1,707 |
| Fuel over five years | $8,535 |
| Against other 4-cyl cars | +$195 a year |
| EPA's own estimate | $2,775 a year |
City or highway — who is this car for
The gap between city and highway figures tells you whom the car suits. A wide gap punishes stop-and-start traffic; a narrow one means the car doesn't care where you drive it.
| Measure | Value | Reading |
|---|---|---|
| City | 20.3 mpg | $1,892 a year if you only drive in town |
| Highway | 26.4 mpg | $1,455 a year if you mostly commute |
| Gap | +6.1 mpg (30%) | Wide — this car dislikes traffic |
How the Onix changed over the years
Combined figure by model year. Jumps usually mark a new generation or a new engine; dips often mean a heavier body or added all-wheel drive.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2026 | 20 / 26 | 2 | $1,707 | |
| 2025 | 20 / 26.5 | 2 | $1,707 | |
| 2024 | 20 / 26.5 | 2 | $1,707 | |
| 2023 | 20.5 / 26.5 | 2 | $1,707 | |
| 2022 | 20.5 / 26.5 | 2 | $1,707 | |
| 2021 | 20.5 / 26.5 | 2 | $1,707 |
MPG is a number. Dollars per year is the answer.
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How we count
Fuel-economy figures come from EPA fueleconomy.gov — the same laboratory numbers printed on the window sticker. We don't adjust them; real-world consumption depends on how and where you drive.
What we add is money. Yearly cost assumes 12,000 miles at $3.20 a gallon — change either and the ranking stays, only the size of the bill moves. Cost per mile is the same figure divided out, useful when comparing a commute against a weekend car.
Frequently asked questions
What mpg does the Chevrolet Onix get?
22.5 mpg combined on average — 20.3 in the city and 26.4 on the highway, per EPA ratings across 2021–2026.
How much does a Chevrolet Onix cost in fuel per year?
About $1,707 at 12,000 miles and $3.20 a gallon — roughly $8,535 over five years, or 0.142 dollars a mile.
Which Onix engine is the most economical?
The 2L 4-cyl at 24 mpg, against 21 for the 3.6L 6-cyl — a difference of about $229 a year.
Is the Onix good on fuel compared with similar cars?
Against other 4-cyl cars it sits below the average of 25.4 mpg, computed across 6877 ratings.
Are these real-world figures?
No — they are EPA laboratory ratings, the same ones on the window sticker. Real consumption depends on driving style, terrain, load and weather, and is typically a little worse.