2025 head-to-head · Midsize Car
2025 Kia K4 vs Mazda 3
MPG, range and what each one really costs you to fuel, from official EPA ratings and recalculated with your own gas and electricity prices.
The 2025 Kia K4 is the cheaper one to run. Driving 15,000 miles a year with $3.10/gal regular gas, it costs about $1,368 a year to fuel (34 MPG), versus $1,500 for the 2025 Mazda 3 (31 MPG). That's roughly $132 a year, or about $662 over five years.
Your numbers
Change these to match your driving and local prices. Every figure and chart on this page updates.
Fuel cost over 10 years
- Kia K4
- Mazda 3
Side by side
| Kia K4 | Mazda 3 | |
|---|---|---|
| $1,368 | Your annual fuel cost | $1,500 |
| 34 MPG | Combined efficiency | 31 MPG |
| 30 MPG | City | 27 MPG |
| 40 MPG | Highway | 37 MPG |
| 99 cu ft | Passenger volume | 93 cu ft |
| 14 cu ft | Cargo volume | 13 cu ft |
| 264 g/mi | Tailpipe CO₂ (g/mi) | 287 g/mi |
| 7/10 | EPA fuel economy score | 6/10 |
| 7/10 | EPA greenhouse gas score | 6/10 |
| Gas | Powertrain | Gas |
| Regular gasoline | Fuel | Regular gasoline |
| 2.0L 4-cyl | Engine / motor | 2.5L 4-cyl |
| CVT | Transmission | 6-speed automatic |
| FWD | Drivetrain | FWD |
✓ marks the better value. EPA scores run 1–10 (10 is best). Volumes come from the EPA interior volume index and aren't published for every body style.
Kia K4 vs Mazda 3 across model years
- Kia K4
- Mazda 3
Annual fuel cost of the most efficient configuration of each model year, at your prices. Click a point to open that year.
How they differ
Per EPA interior volume figures, the Kia K4 has more passenger space (99 vs. 93 cu ft); the Kia K4 has more cargo space (14 vs. 13 cu ft).
Among 42 2025 midsize cars, the Kia K4 ranks 15th and the Mazda 3 18th for lowest fuel cost.
Frequently asked questions
Which is more fuel-efficient, the 2025 Kia K4 or the 2025 Mazda 3?
Measured by cost to drive, the Kia K4. The Kia K4 is rated 34 MPG combined and the Mazda 3 31 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2025 Kia K4 vs. the Mazda 3 per year?
At 15,000 miles a year with $3.10/gal regular gas, about $1,368 for the Kia K4 and $1,500 for the Mazda 3.
Which has more cargo space?
The Kia K4, with 14 cu ft of luggage volume versus 13 cu ft (EPA interior volume index).
Kia K4 vs Mazda 3 in other years
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