K5 vs Mirai
The K5 and the Mirai sit in the same midsize sedan class, but Kia and Toyota don’t always agree on what matters most. This one has a front-runner. The K5 wins 2 of 3 compared areas, and space & practicality is where the difference is hardest to miss.
At a glance
- Engine & Performance Mirai wins
- Space & Practicality K5 wins
- Off-road & Towing K5 wins
- Engine & Performance2.7
- Engine & Performance5.6
Spec scores (0 to 10) are calculated from manufacturer specs against other models in the same class. See how the formula works. They are not reviews or user ratings.
Key Differences
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The K5 has 67% more cargo space
The Mirai is clearly behind on cargo (behind rear seats) (9.6 cu ft against 16 cu ft), and that’s one of its biggest weak spots in this matchup. The K5’s larger cargo area makes family trips and big shopping runs easier.
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The Mirai has 40 lb-ft more torque
On this line of the spec sheet, the Mirai is in a different league: 221 lb-ft, next to 181 lb-ft for the K5. Electrified powertrains deliver torque instantly, so compare torque figures alongside the powertrain type.
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The K5 has available all-wheel drive
You won’t find this on the Mirai. With the K5, it’s part of the package. The K5 offers all-wheel drive; the Mirai doesn’t, which matters if you face harsh winters.
Design & Size
Both come in at nearly the same overall dimensions, so pick on other grounds.
Dimensions
| Spec | K5 | Mirai |
|---|---|---|
| Length | 193.1 in | 195.8 in |
| Width (no mirrors) | 73.2 in | 74.2 in |
| Height | N/A (not specified) | 57.9 in |
| Wheelbase | 112.2 in | 114.9 in |
Engine & Performance
Mirai leads
The Mirai wins the engine & performance section decisively. The Mirai comes with 40 lb-ft more torque. More torque means stronger pulling from low speeds, which you feel when accelerating from a stop or climbing grades. For engine & performance, the Mirai is the one to beat.
Torque
K5: 181 lb-ft Mirai: 221 lb-ft The Mirai’s extra torque makes it more relaxed when fully loaded or towing.
Space & Practicality
K5 leads
The Mirai has a tough time in the space & practicality section, where the K5 pulls well ahead. On the K5, you get 67% more cargo space. Cargo figures are measured in different ways by different makers, so small gaps may not show in practice. The takeaway: on space & practicality, the K5 is the stronger car.
Cargo (behind rear seats)
K5: 16 cu ft Mirai: 9.6 cu ft Cargo space behind the rear seats is what you use every day for groceries, strollers and luggage.
Off-road & Towing
K5 leads
By a small margin, the K5 is the stronger of the two in this area. The K5 brings available all-wheel drive. Available all-wheel drive improves traction in rain, snow and on loose surfaces. Bottom line for off-road & towing: the K5 has the edge.
AWD / 4WD available
K5: yes Mirai: no All-wheel drive helps you get going on slippery roads, but good tires matter just as much for stopping and turning.
Safety & Tech
This area doesn’t reduce to a single number. The table shows the safety & tech details for both, so you can judge what matters to you.
Full Specifications
Engine & Performance
| Spec | K5 | Mirai |
|---|---|---|
| Powertrain | Gas | Hydrogen fuel cell |
| Engine | 2.5L I4 | Fuel cell stack + electric motor (134 kW) |
| Total system output | 191 hp | 182 hp |
| Torque | 181 lb-ft | 221 lb-ft (winner) Most torque in class |
| Transmission | 8-speed automatic | Single-speed |
| Drivetrain | FWD (AWD available) | RWD |
Fuel Economy & Range
| Spec | K5 | Mirai |
|---|---|---|
| Fuel economy (combined)EPA estimate where available | 30 mpg | N/A (not specified) |
| Fuel economy (city) | 26 mpg Thirstiest in the city | N/A (not specified) |
| Fuel economy (highway) | 37 mpg | N/A (not specified) |
Space & Practicality
| Spec | K5 | Mirai |
|---|---|---|
| Seats | 5 seats | 5 seats |
| Cargo (behind rear seats) | 16 cu ft (winner) | 9.6 cu ft Smallest cargo area |
Off-road & Towing
| Spec | K5 | Mirai |
|---|---|---|
| AWD / 4WD available | Yes (winner) | No |
Safety & Tech
| Spec | K5 | Mirai |
|---|---|---|
| Largest touchscreen | N/A (not specified) | 12.3 in |
| Driver-assist suite | Kia Drive Wise | N/A (not specified) |
| Basic warranty | 5 yr / 60,000 mi | 3 yr / 36,000 mi |
Dimensions
| Spec | K5 | Mirai |
|---|---|---|
| Length | 193.1 in | 195.8 in |
| Width (no mirrors) | 73.2 in | 74.2 in |
| Height | N/A (not specified) | 57.9 in |
| Wheelbase | 112.2 in | 114.9 in |
Price
| Spec | K5 | Mirai |
|---|---|---|
| Starting MSRP | N/A (not specified) | $51,795 Priciest in class |
“N/A” means the manufacturer does not specify the value or we could not confirm it. Figures marked “manufacturer rating” are the maker’s own claims, not our measurements.
Which One Should You Buy?
Choose the K5 if…
- you want more cargo space behind the rear seats (16 cu ft vs 9.6 cu ft)
- you want all-wheel drive available
- you prefer staying with Kia
Choose the Mirai if…
- you want more pulling power from low speeds (221 lb-ft vs 181 lb-ft of torque)
- you already use other Toyota products
Also Compared
Frequently Asked Questions
Which is better for most people, the K5 or the Mirai?
The K5 makes more sense overall. Consider the alternative only if you need 40 lb-ft more torque, which only the Mirai offers.
Is the K5 bigger than the Mirai?
The K5 and the Mirai are so close in size that you’d struggle to tell them apart on dimensions alone.
Executive Summary
The K5 against the Mirai: two brands, one class, and more nuance than the marketing suggests. Honestly, 67% more cargo space on the K5 does a lot of the persuading for me. The K5 also scores with available all-wheel drive. In fairness to the Mirai, 40 lb-ft more torque is a genuine strength.
The K5 is for you if space & practicality tops your list; the Mirai is for you if engine & performance does.
My pick: the K5 is the one I’d buy, unless your top priority is 40 lb-ft more torque.
Personal opinion based on the data above. Your priorities may differ.