Current class limits
Every kei truck in production is built to these figures. They are regulatory ceilings, not typical values, so almost all trucks sit within a few millimetres of them.
| Parameter | Limit |
|---|---|
| Engine displacement | 660cc maximum |
| Length | 3.40 m (11 ft 2 in) maximum |
| Width | 1.48 m (4 ft 10 in) maximum |
| Height | 2.00 m (6 ft 7 in) maximum |
| Rated payload (truck) | 350 kg (about 770 lb) |
| Power (voluntary industry cap) | 64 PS, roughly 63 hp |
How the limits changed
The class has been redefined several times. This matters when reading old listings: a "kei truck" from 1980 is a materially smaller vehicle than one from 2000.
| Period | Displacement | Maximum dimensions | Notes |
|---|---|---|---|
| 1949–1954 | 150–360cc | 3.00 m × 1.30 m × 2.00 m | The kei category is created in post-war Japan. Displacement limits rise repeatedly in the early years as the class finds its footing. |
| 1955–1975 | 360cc | 3.00 m × 1.30 m × 2.00 m | The long 360cc era. Most trucks of this period are two-stroke or small four-stroke and are now of collector rather than working interest. |
| 1976–1989 | 550cc | 3.20 m × 1.40 m × 2.00 m | Displacement rises to 550cc and the body box grows. Honda's TN and Acty and the early Suzuki Carry generations sit here. |
| 1990–1997 | 660cc | 3.30 m × 1.40 m × 2.00 m | The 660cc limit arrives — still the limit today. This is where the modern usable kei truck begins. |
| 1998–present | 660cc | 3.40 m × 1.48 m × 2.00 m | The body box is enlarged again, mainly for crash safety. Trucks from this era are the most common imports and the most practical to use. |
The 1998 revision widened the box to 1.48 m and lengthened it to 3.40 m, largely to allow better crash structures. Trucks built after it have noticeably more cabin room, and are the ones most buyers find comfortable to actually use.
Models compared
| Model | Maker | In production since | Typical engine | Engine position |
|---|---|---|---|---|
| Suzuki Carry | Suzuki | 1961 | K6A | Front-mid engine under the seats |
| Daihatsu Hijet | Daihatsu | 1960 | KF-VE | Front-mid engine under the seats |
| Honda Acty | Honda | 1977 | E07Z | Mid engine under the cargo bed |
| Subaru Sambar | Subaru | 1961 | EN07 | Rear engine |
| Mitsubishi Minicab | Mitsubishi | 1966 | R06A | Front-mid engine under the seats |
Engines
Three cylinders and roughly 658cc is the norm. The Subaru EN07 is the outlier with four.
| Code | Maker | Type | Years | Notes |
|---|---|---|---|---|
| F6A | Suzuki | 657cc SOHC/DOHC 3-cyl | 1990–2000s | Carburettor and EFI versions. Widely used across Carry and Every. |
| K6A | Suzuki | 658cc DOHC 3-cyl | 1994–2013 | EFI, chain-driven cam on later units. Also used in Jimny. |
| R06A | Suzuki | 658cc DOHC 3-cyl | 2013– | Current Suzuki kei engine, also used in rebadged Minicab and Clipper. |
| EF-series | Daihatsu | 659cc 3-cyl | 1990s–2000s | EF-SE, EF-GS, EF-VE variants across Hijet and Atrai. |
| KF | Daihatsu | 658cc DOHC 3-cyl | 2005– | Replaced the EF family; used in later Hijet and rebadged Subaru/Toyota kei. |
| E05A | Honda | 547cc 3-cyl | 1988–1990 | Final 550cc-era Acty engine. |
| E07A / E07Z | Honda | 656cc 3-cyl | 1990–2021 | Mid-mounted in the Acty. E07Z is the later revision. |
| EN07 | Subaru | 658cc 4-cyl | 1989–2012 | Four cylinders, unusual for the class. Supercharged versions offered. |
| 3G83 | Mitsubishi | 657cc 3-cyl | 1990–2014 | Long-lived Minicab and Town Box engine. |
Payload
The Japanese rated payload for a kei truck is 350 kg, about 770 lb. Brakes, suspension, tyres and the rear axle are specified around that number. Owners routinely exceed it; the rating is what the vehicle was designed and type-approved for.