The 2025 Kia K4 gets 29 to 34 miles per gallon combined, depending on the version. The best is the 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2 at 34 mpg.
In the Midsize Cars class for 2025, the K4 ranks 8th (tied with 1 other) of 32 for combined mileage (34 mpg), 8th (tied with 1 other) of 30 for yearly fuel cost ($1,850 for its cheapest version, cheapest first) and 12th of 32 for tailpipe CO2 (264 grams per mile for its lowest version, lowest first). The middle model of the class gets 29 mpg, costs $2,575 a year and puts out 289.5 grams per mile.
Across all 250 2025 models in the file that burn fuel, the middle best-version figure is 25 mpg and the highest is 57 mpg (Toyota Prius). Of the 249 other models, 29 get more miles per gallon than the 2025 K4's best version, 1 other model gets the same and 219 get less. The 2025 K4's cheapest version costs $1,850 a year to fuel by the agency's figure; of the 241 other models with a cost figure, 27 cost less, 1 the same and 213 more.
Open the best-mileage list of this class for 2025. Cost and CO2 in the table are each model's lowest figure over its versions; plug-in hybrid and fuel-cell versions have no fuel cost and are left out of the cost column.
| Place | Model | Best version | mpg | Fuel a year, cheapest version | CO2 g/mi, lowest version |
|---|---|---|---|---|---|
| 5 | 2025 Honda Accord | 2025 Accord Hybrid Sport/Touring | 44 | $1,400 | 201 |
| 5 | 2025 Lexus ES | 2025 ES 300h | 44 | $1,400 | 200 |
| 7 | 2025 Toyota Crown | 2025 Crown AWD (4-cyl 2.5 L) | 41 | $1,500 | 214 |
| 8 | 2025 Kia K4This car | 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2 | 34 | $1,850 | 264 |
| 8 | 2025 Nissan Sentra | 2025 Sentra | 34 | $1,850 | 262 |
| 10 | 2025 Nissan Kicks | 2025 Kicks Play | 33 | $1,900 | 268 |
| 11 | 2025 BMW 5 Series | 2025 530i Sedan | 31 | $2,500 | 135 |
Pick a 2025 version, then set your miles and fuel price. Fuel price as of 2026-11-14, U.S. Department of Energy / EPA. The price box starts at the dated price of the fuel the picked version burns (regular, midgrade or premium gasoline, diesel, E85 or electricity) and sets the price of that fuel. Miles are limited to 1,000 to 60,000 a year and the price to $0.01 to $20.00; a value outside that is worked out at the nearest limit.
2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2, 4-cyl 2.0 L: 30 mpg city, 40 highway, 34 combined. The agency's own estimate for the 2025 K4 version is $1,850 a year (15,000 miles, the agency's fuel prices).
The 3 nearest rivals in the Midsize Cars class for 2025, picked by closest combined mileage; only versions with a fuel-cost figure are listed. Same miles as on the left. The price box on the left is the price of the fuel of the version you picked: a rival that burns the same fuel uses that price, a rival that burns another fuel keeps the dated price of its own fuel. The 5-year line is 5 times the yearly gap.
Both cost the same to fuel.
Over 5 years both cost the same to fuel at these miles and these prices.
Dollar gaps use each car's best-mileage version.
| Rival in 2025 | Best version | Combined | Fuel a year, agency (15,000 miles) | Against the K4 (mileage) | Agency yearly fuel cost against the K4 | Side by side |
|---|---|---|---|---|---|---|
| 2025 Nissan Sentra | 2025 Sentra | 34 mpg | $1,850 | same figure | same | Compare |
| 2025 Nissan Kicks | 2025 Kicks Play | 33 mpg | $1,900 | 1 lower | $50 more a year | Compare |
| 2025 BMW 5 Series | 2025 530i Sedan | 31 mpg | $2,500 | 3 lower | $650 more a year | - |
EPA test figures for 2025; the last column is the yearly fuel cost against the cheapest version.
| Version | Engine | Gearbox | Drive | City | Highway | Combined | Fuel a year | CO2 g/mi | Fuel vs cheapest |
|---|---|---|---|---|---|---|---|---|---|
| 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2 | 4-cyl 2.0 L | Automatic (AV-S1) | Front-wheel | 30 | 40 | 34 | $1,850 | 264 | cheapest |
| 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #1 | 4-cyl 2.0 L | Automatic (AV-S1) | Front-wheel | 29 | 39 | 33 | $1,900 | 273 | +$50 |
| 2025 K4 (4-cyl 1.6 L, Automatic (S8)) #3 | 4-cyl 1.6 L | Automatic (S8) | Front-wheel | 26 | 36 | 29 | $2,150 | 303 | +$300 |
Enter the price difference you were quoted for the 2025 K4; this page has no prices. Miles come from the calculator. The fuel price box there sets the price of the fuel of the version picked there; a version here that burns another fuel keeps the dated price of its own fuel. Versions with no fuel-cost figure are not listed.
Type the price difference you were quoted to see the payback.
Tailpipe CO2: the 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2 puts out 264 grams per mile; across the 3 tested versions the figure runs from 264 to 303.
EPA scores (1 to 10, 10 best) for the 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2: fuel economy score 7 (6 to 7 across versions), greenhouse gas score 7 (6 to 7 across versions).
Best combined figure of the K4 gas version each model year since 2016, set against the 2025 model.
| Model year | Best gas version | Versions tested | Against 2025 | |
|---|---|---|---|---|
| 2025This page | 34 mpg | 3 | this page | |
| 2026 | 33 mpg | 5 | 1 mpg lower than 2025 |
No 2024 Kia K4 is in the agency's file, so there is no earlier year to compare with.
The 2026 model has 5 tested versions.
Crash-test stars from the U.S. safety agency's 5-Star Safety Ratings, checked 2026-11-14. 5 is the best.
| Vehicle | Overall | Front | Side | Rollover |
|---|---|---|---|---|
| 2025 KIA K4 4 DR FWD | 5 of 5 | 4 of 5 | 5 of 5 | 5 of 5 |
The agency's record for the first rated vehicle also lists 53 complaints, 2 recalls, 0 investigations.
53 complaints for the 2025 Kia K4 are on file (checked 2026-11-14). Complaints are reports that owners sent to the safety agency. They are not proven defects, and the counts are not adjusted for how many cars were sold.
| Part named in the reports | Reports | |
|---|---|---|
| Electrical System | 16 | |
| Unknown Or Other | 13 | |
| Power Train | 9 | |
| Engine | 8 | |
| Lane Departure | 8 |
11 of the 53 reports say the car was in a crash, 1 mentions a fire and 6 mention an injury. One report can name more than one part.
2 recalls are on file for the 2025 Kia K4 at the U.S. safety agency (checked 2026-11-14). A dealer does recall repairs free of charge.
Kia America, Inc. (Kia) is recalling certain 2025 Kia K4, 2025-2026 Sorento, Sorento Hybrid, Sorento Plug-In Hybrid Electric (PHEV), 2026 Sportage, Sportage Hybrid, Sportage PHEV, K5, EV9, Carnival, and Carnival Hybrid vehicles.
Fix: The instrument panel display software will be updated over-the-air (OTA) or by a dealer, free of charge. Owner notification letters are expected to be mailed March 26, 2026.
Kia America, Inc. (Kia) is recalling certain 2025 K4 and Sorento vehicles. The connecting rod bolts in the engine may have been improperly tightened, which can cause a loss of drive power.
Fix: Dealers will replace the sub engine assembly, free of charge. Owner notification letters are expected to be mailed September 12, 2025. Owners may contact Kia customer service at 800-333-4542.
Other 2025 models of the same agency class, each with its best combined figure. The K4 itself is at 34 mpg.
More Kia models that have a 2025 page here, with the class of each and its best combined figure.
The 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2 with 34 mpg combined (30 city, 40 highway).
The 2025 Kia K4 costs between $1,850 and $2,150 to fuel by the agency's estimate, which assumes 15,000 miles a year. The cheapest is the 2025 K4 (4-cyl 2.0 L, Automatic (AV-S1)) #2 at $1,850; the dearest is the 2025 K4 (4-cyl 1.6 L, Automatic (S8)) #3 at $2,150. Use the calculator above for your own miles and fuel price.
The 2025 Kia K4 is 8th of 32 for combined mileage. The top of the class is the 2025 Toyota Prius at 57 mpg, and the middle figure for the class is 29 mpg. In the list, the next one ahead is the 2025 Toyota Crown at 41 mpg and the next one behind is the 2025 Nissan Sentra at 34 mpg.
In the agency's 5-Star Safety Ratings (checked 2026-11-14; 5 is the best), the stars are 2025 KIA K4 4 DR FWD: overall 5 of 5, front 4, side 5, rollover 5.
53 complaints for the 2025 Kia K4 are on file at the safety agency (checked 2026-11-14); the part named most often is Electrical System (16 reports). Complaints are reports owners sent in, not proven defects.
The agency's database lists 2 recalls for the 2025 Kia K4 (checked 2026-11-14). They are listed above with the repair the maker offers.
For the 2025 Kia K4: EPA file 2026-11-04; fuel price 2026-11-14; crash tests 2026-11-14; complaints 2026-11-14; recalls 2026-11-14. Not covered: purchase price, towing, reliability, repair and insurance costs.
Mileage and fuel cost for the 2025 Kia K4: U.S. Environmental Protection Agency, fueleconomy.gov vehicle file (file dated 2026-11-04). Recalls for the 2025 Kia K4: U.S. National Highway Traffic Safety Administration (checked 2026-11-14). Crash-test ratings for the 2025 Kia K4: NHTSA 5-Star Safety Ratings (checked 2026-11-14). Complaints for the 2025 Kia K4: NHTSA (checked 2026-11-14). Fuel prices: U.S. Department of Energy / EPA (2026-11-14). Your own mileage depends on how and where you drive. Where our numbers come from.