How many cc is a kei car?
Kei cars are limited by an engine displacement cap of 660 cc, which is the maximum size permitted for most models in this category.
In Japan, kei cars are a distinct regulatory class designed to promote compact, economical urban mobility. Beyond the displacement limit, the category also imposes strict size and power requirements, which collectively keep these vehicles small and affordable. This article explains the current cc limit and related rules.
What defines a kei car
Kei cars are regulated to be exceptionally compact and efficient. The most widely cited numerical constraint is the engine displacement cap for traditional internal combustion models, but the category also includes limits on overall dimensions and engine power.
Engine displacement cap
The engine displacement cap for ICE kei cars is currently 660 cubic centimeters (cc). This figure is the cornerstone of the kei car classification and has been maintained to support affordable, low-emission urban mobility.
Other limits
In addition to displacement, kei cars must meet size and power limits: maximum length of 3.4 meters, width of 1.48 meters, height of 2.0 meters, and a capped engine output around 47 kW (about 64 horsepower) for internal combustion models. These constraints together define what can be marketed as a kei car in Japan.
Key numerical limits that define the kei category are summarized below for quick reference:
- Engine displacement: up to 660 cc for ICE kei cars
- Maximum power: up to about 47 kW (64 horsepower) for ICE kei cars
- Dimensions: length up to 3.4 m, width up to 1.48 m, height up to 2.0 m
These constraints ensure kei cars remain ultra-compact and fuel-efficient, and they help explain why most new kei models sit at or near the 660 cc cap.
Electric kei cars
There are electric models that fall under the broader kei car category, which follow the same spirit of compact size and efficiency. In these cases, the classification emphasizes footprint and performance limits rather than engine displacement, since electric powertrains do not use cc in the same way as internal combustion engines.
Summary
In short, a kei car in Japan is defined by an engine displacement cap of 660 cc for its internal combustion engines, along with tight size and power restrictions. This regulatory framework exists to promote affordable, practical urban mobility, resulting in a distinctive class of vehicles that are easy to park, tax, and operate in crowded cities.
