2026 Kia K5 w/Stop-Start: MPG and fuel economy
The 2026 Kia K5 w/Stop-Start is rated by the U.S. Environmental Protection Agency at 30 combined MPG, with 26 MPG in the city and 37 MPG on the highway. That lands well below the average for cars in the Large Cars class in the same model year.
This page collects every fuel-economy figure the EPA publishes for the 2026 Kia K5 w/Stop-Start. Below you will find the headline combined, city, and highway MPG, the estimated annual fuel cost at three different driving levels, the tailpipe CO₂ emissions, and a full breakdown of the engine and drivetrain.
Key takeaways
- Returns 48% worse combined MPG than the average car in the Large Cars class for the 2026 model year (58.1 MPG class average).
- The most efficient car in the Large Cars class for the 2026 model year is the Lucid Air Pure RWD with 19 inch wheels at 146 MPG.
Fuel economy at a glance
These are the EPA's official ratings for the 2026 Kia K5 w/Stop-Start. The numbers come from a standardised laboratory test cycle and are the same figures that appear on the window sticker of every new car. Real-world mileage varies with driving style, weather, fuel quality, and how heavily loaded the car is.
Combined MPG is a 55/45 weighted blend of the city and highway test cycles. The EPA uses it as the single number you can compare across the entire dataset, including hybrids and EVs (which use the equivalent MPGe figure).
| Combined MPG | 30 MPG |
| City MPG | 26 MPG |
| Highway MPG | 37 MPG |
| Annual fuel cost | $2,000 |
| Tailpipe CO₂ | 298 g/mi |
| Fuel type | Regular |
How the 2026 Kia K5 w/Stop-Start compares
The 2026 Kia K5 w/Stop-Start returns 30 combined MPG. Cars in the Large Cars class for the same model year average 58.1 MPG, which puts this car behind the class average by about 48%.
The most efficient car in the Large Cars class for the 2026 model year is the Lucid Air Pure RWD with 19 inch wheels at 146 MPG. The bar chart below puts the Kia K5 w/Stop-Start alongside the class best and the class average so you can see the full picture.
For broader context, the average new car of the 2026 model year (across all classes) returns 45.5 MPG. Larger vehicles pull the all-cars average down, so do not use that figure on its own to judge a small car or a hybrid. The full list of the most efficient cars of the 2026 model year is on its own page.
Annual fuel cost across driving patterns
The headline annual fuel cost the EPA publishes assumes 15,000 miles of driving per year and a fuel mix of 55% city and 45% highway. The dollar figure is calculated using the EPA's current reference price for regular gasoline, which is $3.99/gallon. EPA updates that reference periodically rather than tracking live pump prices, so treat it as a window-sticker estimate rather than today's pump number.
The table below scales the EPA's number to three common driving patterns. The combined MPG and the reference fuel price stay constant, only the annual mileage changes. To get a current-prices estimate, take your local gas price and multiply by 500 gallons (the car's annual consumption at the rated MPG).
| Driving pattern | Estimated annual fuel cost |
|---|---|
| Light driver, 7,500 miles per year | $1,000 |
| Average driver, 15,000 miles per year | $2,000 |
| Heavy driver, 25,000 miles per year | $3,333 |
Compare against other Large Cars for 2026
If you are cross-shopping the 2026 Kia K5 w/Stop-Start, the most useful comparison is against the other cars in the Large Cars class for the same model year. The list below shows the highest-MPG peers, ranked from most to least efficient. Click any of them to open its full page.
The Lucid Air Pure RWD with 19 inch wheels leads this group at 146 MPG, 116 MPG ahead of the 2026 Kia K5 w/Stop-Start.
Specifications
The 2026 Kia K5 w/Stop-Start runs a 2.5-liter 4-cylinder engine paired with a automatic (s8), sending power through front-wheel drive.
Engine, transmission, and drivetrain together drive most of the variation in fuel economy across trims. A larger engine moves the car with less effort but burns more fuel. A turbo lets a small engine punch above its weight, often without much MPG penalty. All-wheel drive adds traction and weight, and usually costs a couple of MPG compared with two-wheel drive of the same engine.
- Vehicle class
- Large Cars
- Engine
- 2.5L 4-cylinder
- Transmission
- Automatic (S8)
- Drivetrain
- Front-Wheel Drive
- Fuel type
- Regular
- Annual petroleum use
- 9.9 barrels per year
- Start-stop system
- Yes
Common questions about the 2026 Kia K5 w/Stop-Start
Quick answers to the questions people most often search for when looking up the 2026 Kia K5 w/Stop-Start.
-
Is the 2026 Kia K5 w/Stop-Start fuel efficient?
Not particularly. The 2026 Kia K5 w/Stop-Start returns 30 combined MPG, which trails the average car in the Large Cars class for the same model year by about 48%. -
What MPG does the 2026 Kia K5 w/Stop-Start get?
The EPA rates the 2026 Kia K5 w/Stop-Start at 30 combined MPG, 26 MPG in city driving, and 37 MPG on the highway. Real-world numbers depend on your driving style, the weather, and how loaded the car is. -
How much does it cost to fuel a 2026 Kia K5 w/Stop-Start per year?
The EPA estimates an annual fuel cost of $2,000 for the 2026 Kia K5 w/Stop-Start. That figure assumes 15,000 miles of driving per year, a 55% city and 45% highway split, and the EPA's published average fuel price for the rated fuel grade. -
What fuel does the 2026 Kia K5 w/Stop-Start use?
The EPA lists the 2026 Kia K5 w/Stop-Start as running on regular gasoline. Using a different grade than the manufacturer specifies can affect fuel economy and engine longevity. -
How much CO₂ does the 2026 Kia K5 w/Stop-Start emit?
Tailpipe CO₂ emissions are 298 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 4,470 kilograms of CO₂. -
What is the difference between the city and highway MPG of the 2026 Kia K5 w/Stop-Start?
City driving returns 26 MPG and highway driving returns 37 MPG, a gap of 11 MPG. A spread that wide is typical of cars with conventional automatic or manual transmissions, where stop-start city traffic eats more fuel than a steady highway cruise. -
What engine is in the 2026 Kia K5 w/Stop-Start?
The 2026 Kia K5 w/Stop-Start has a 2.5-liter 4-cylinder engine (EPA description: SIDI & PFI). -
What transmission and drivetrain does the 2026 Kia K5 w/Stop-Start have?
The 2026 Kia K5 w/Stop-Start comes with a automatic (s8) transmission and front-wheel drive. -
How does the 2026 Kia K5 w/Stop-Start compare to the best car in its class?
The most efficient car in the Large Cars class for the 2026 model year is the Lucid Air Pure RWD with 19 inch wheels at 146 combined MPG. The Kia K5 w/Stop-Start returns 30 MPG, a gap of 116 MPG. If you are comparing on fuel economy alone, the class leader is worth a look. -
How much petroleum does the 2026 Kia K5 w/Stop-Start use per year?
The EPA estimates the 2026 Kia K5 w/Stop-Start consumes about 9.9 barrels of petroleum per year, based on the standard 15,000 miles of driving. A barrel is 42 U.S. gallons of crude oil, which is refined into gasoline plus other products.
Source: U.S. EPA fuel economy dataset. Annual fuel cost figures assume 15,000 miles of driving per year and a 55% city, 45% highway split. Real-world mileage varies with driving conditions, vehicle maintenance, fuel quality, and driver behaviour.