You don't need us to tell you that the Japanese car market is about as far-removed from the U.S. market as it's possible to get.

Where big trucks still dominate in North America, vehicles that almost fit in the average truck's pickup bed make up almost half of all Japanese car sales.

Those cars are known as kei cars, or keijidōsha--"light automobiles".

Size matters

Conforming to a strict set of rules and regulations, Japan's smallest offerings started like their tiny counterparts in Europe, providing inexpensive transport in the post-war era.

But as Japan's roads became ever more crowded, their purpose shifted slightly--tight physical dimensions and small engine capacities keep size to a minimum, exempting them from Japan's rule that any larger car must have a suitable parking space. They also cut useful sums from Japan's numerous automobile taxes.

A whole industry has grown up around keijidōsha, with everything from passenger vehicles, vans and pickups all available as kei cars--even sports cars, on occasion.

Nissan DAYZ kei-class minicar

Nissan DAYZ kei-class minicar

None are longer than 11.2 feet, wider than 4.9 ft or taller than 6.6 ft. All are limited to 660cc engine capacity, and 63 horsepower.

For comparison, a Smart Fortwo is shorter at 8.8 feet and lower at just over 5 ft tall, but wider at 5.1 ft, has a larger, 1-liter engine, and puts out 70 horsepower in U.S. specification.

Not all are as boxy as the Nissan Dayz and Mitsubishi EK Wagon you see in the video above--retro designs like the Honda N-One we drove last year are popular--but maximizing the car's exterior dimensions within the regulations ensures interior space is as large as possible. You'd be surprised how large some of these vehicles are inside.

The U.S. market kei?

Given their incredibly compact size it's no surprise such cars aren't sold in the U.S, though one vehicle gets close. The all-electric Mitsubishi 'i', or i-MiEV, is based on a kei-class car of the same name sold in several other markets around the world.

While the standard 'i' neatly meets kei regulations in terms of size (and engine capacity, in the gasoline variant), the U.S. version was widened by over 4 inches and stretched by almost a foot. This helps it meet U.S. crash regulations, and also makes it a little more suitable for the average American's larger frame than their Japanese counterpart...

1970 Honda N600 (Image: Wikimedia Commons)

1970 Honda N600 (Image: Wikimedia Commons)

It's not the only kei-class car to have ever hit the U.S, either. Around 10,000 Subaru 360s hit the U.S. back in the 1960s, and with a larger engine for the U.S. market, Honda exported its N600 (based on the kei-class N360) in the late 1960s and early 70s.

The N600 was eventually replaced by the Civic--and with that, the rest is history.


Some kei cars were traditionally rather spartan inside and used quite basic mechanicals, but like any other vehicle these days, modern keis are remarkably high-tech.

Continuously-variable transmissions are common and in-car entertainment systems abound--you may as well keep yourself amused while stuck in endless Tokyo traffic.

Their ubiquity also makes them a popular part of Japan's tuning culture, with dedicated events and race series not unknown. At the other end of the scale, kei vans and pickups dominate Japan's light commercial vehicle industry.

Really, they're exactly as they seem--regular cars, just in miniature scale.

And while they'd struggle to sell in the U.S. among huge, imposing SUVs and trucks, they're as much a product of their environment as the Ford F-Series is in the States. But a little more fuel-efficient, too...


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