The Kia K4 does 33.5 mpg combined (29.5 city, 39.5 highway), which works out to about $1,146 a year in fuel at $3.20 a gallon and 12,000 miles. Against other 4-cyl cars it sits above the average of 25.7 mpg.
Every Kia K4 engine, compared
The Kia K4 was rated in a single specification, so its gas mileage does not vary by version — only by model year. Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 2L 4-cyl | 29.5 / 39.5 | 2025–2026 | $1,146 |
What that actually costs
The Kia K4 burns a gallon every 33.5 miles, so 12,000 miles takes about 358 gallons a year. At $3.20 that is what the table below adds up to.
| Measure | Value |
|---|---|
| Cost per mile | $0.096 |
| Fuel per year | $1,146 |
| Fuel over five years | $5,730 |
| Against other 4-cyl cars | −$348 a year |
| EPA's own estimate | $1,875 a year |
City or highway — who is this car for
The Kia K4 gives up 10 mpg the moment you leave the motorway — 39.5 out there against 29.5 in town, a 34% drop worth $330 a year. 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 | 29.5 mpg | $1,302 a year if you only drive in town |
| Highway | 39.5 mpg | $972 a year if you mostly commute |
| Gap | +10 mpg (34%) | Wide — this car dislikes traffic |
How the K4 changed over the years
The K4 peaked in 2025 at 34 mpg (30 city, 40 highway) and was at its thirstiest in 2026 at 33 — 1 mpg apart, or $35 a year in fuel between buying one year and the other. The 2026 car does 33.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2026 | 29 / 39 | 1 | $1,164 | |
| 2025 | 30 / 40 | 1 | $1,129 |
MPG is a number. Dollars per year is the answer.
- Fuel profile built from your actual mileage and local prices
- Fuel tracker: what you really spend, month by month
- Insurance and fuel folded into 5-year cost to own
- Compare any two cars on total cost, not sticker price
- No ads, no tracking — and much more
How we count
This page rests on 2 EPA ratings of the Kia K4 — 1 engine across 2025–2026. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $1,875. Full method.
Frequently asked questions
What mpg does the Kia K4 get?
33.5 mpg combined on average — 29.5 in the city and 39.5 on the highway, per EPA ratings across 2025–2026.
How much does a Kia K4 cost in fuel per year?
About $1,146 at 12,000 miles and $3.20 a gallon — roughly $5,730 over five years, or 0.096 dollars a mile.
Which K4 engine is the most economical?
The 2L 4-cyl at 33.5 mpg.
Is the K4 good on fuel compared with similar cars?
Against other 4-cyl cars it sits above the average of 25.7 mpg, computed across 4765 ratings.
Are these real-world K4 figures?
No — they are EPA laboratory ratings, the same ones printed on the window sticker, and EPA's own annual fuel estimate for the Kia K4 is $1,875 against the $1,146 we compute at 12,000 miles. Expect a little worse in practice: the spread between the city and highway figures is smaller than the spread between two drivers of the same one.
Mark ForCar as a preferred source and our data shows up first in your Google results. One click, no account.