The History of Japan’s Kei Cars (1949-1972): Part 1

Original by: Enthusiastic Citizen Zhang | Japanese Car Enthusiasts Magazine Updated: Today at 10:00 AM

Japan is renowned as a major automobile manufacturing country, producing cars known for their fuel efficiency and compactness. These vehicles, with their unique design philosophy, have carved out a distinct identity in the global auto industry. However, the cars that dominate Japan’s domestic market differ significantly from the Japanese-made vehicles familiar to international consumers.+

One often sees uniquely Japanese cars on the streets, resembling toy cars—small, light, and whimsical. These tiny cars, while seemingly unsafe for use in countries like China, are perfectly suited for Japan’s domestic landscape.

Kei cars (K-cars) are a uniquely Japanese product born out of post-war economic necessity. Their development reflects two major influences: the economic hardship following World War II, which prompted manufacturers to create ultra-compact cars for everyday mobility, and Japan’s unique spatial constraints. These cars also became a solution to traffic congestion as the economy improved. Additionally, as more families considered purchasing second cars, Kei cars gained popularity. Since their inception in 1949, Kei cars have sold over ten million units, demonstrating their significant demand.

🌟 Hello, my friend...

Welcome to a hidden gem—OLD FISHER DISCOUNT, your one-stop online shop with 9,999+ unique finds waiting for you. 🎉

🛒 Explore a World of Discoveries
Dive into our collection and uncover special treasures that will delight and inspire.

🔗 Start Your Journey Here: www.fisherdiscount.com
Come and see why we’re more than just a shop; we’re a place of endless possibilities! ✨

What is a Kei Car?

According to the Japan Kei Car Association, a Kei car must meet the following criteria:

• Length: 3.4 meters or less

• Width: 1.48 meters or less

• Engine displacement: Not exceeding 660cc

These specifications were introduced in October 1998. Initially, when Kei cars were established in 1949, the requirements were even stricter: a length of no more than 2.8 meters, a width under 1 meter, and engine displacements limited to 100cc for two-stroke engines or 150cc for four-stroke engines. Let’s travel back in time to explore the 70-year evolution of Kei cars.

1. Dawn of Kei Cars (110/150cc)

In July 1949, Japan’s Ministry of Transportation amended the 36th "Vehicle Rules," officially introducing the term "Kei car" to categorize ultra-compact automobiles. Under this regulation, Kei cars were defined as:

• Length: 2.8 meters or less

• Width: 1 meter or less

• Height: 2 meters or less

• Engine Displacement: 150cc (four-stroke) or 100cc (two-stroke)

• 

No restrictions were placed on the number of wheels; only size and engine capacity were specified.

2. Early Expansion (200/300cc)

In July 1950, the Kei car standards were revised:

• Four-wheel vehicles: Engine displacement up to 300cc

• Two-wheel vehicles: Engine displacement up to 200cc

• Dimensions: Length of 3 meters or less, width of 1.3 meters or less, height of 2 meters or less

This amendment added classifications for four-wheel (modern Kei cars), three-wheel (small tricycles), and two-wheel vehicles (light motorcycles).

3. Prevalence (240/360cc)

In August 1951, the Ministry of Transportation amended the "Road Transport Vehicle Law Implementation Rules," establishing engine displacement limits of:

• 360cc (four-stroke engines)

• 240cc (two-stroke engines)

Key Developments:

• 1953: Auto Sandal Manufacturing Co. produced Japan’s first mass-produced Kei car, the FS model, equipped with a 240cc two-cylinder two-stroke engine.1953: Japan Auto Industry introduced the NJ model with a 358cc V2 air-cooled OHV engine, achieving a top speed of 60 km/h.

4. Major Manufacturers Enter the Market (360cc)

By the mid-1950s, major automakers began producing Kei cars:

• Suzuki (1955): The first-generation Sunlight featured a 360cc two-cylinder two-stroke engine, reaching a top speed of 85 km/h.

• Daihatsu (1957): The Midget tricycle gained popularity among small businesses for its practicality and fuel efficiency, achieving 28 km/L.

• Subaru (1958): The Subaru 360—a charming, rear-engine compact car—became a national favorite with nearly 400,000 units sold over 12 years.

• Mazda (1960): The R360 Coupe, a two-door four-seater, offered both manual and automatic transmission options, selling over 20,000 units in its first year.

5. The Honda Revolution

Honda made significant contributions to Kei car development:

• 1963 (T360): Honda’s first automobile, a commercial truck, utilized a 360cc DOHC engine producing 30 hp.

• 1967 (N360): Honda’s N360, with its revolutionary 31 hp engine, became an instant success, selling over 25,000 units within two years and accumulating a total production of 650,000 units.

6. Pioneering Models of the Late 1960s and Early 1970s

Other notable Kei cars included:

• Subaru R-2 (1969): A successor to the 360, featuring a more practical design and improved performance.

• Suzuki Jimny (1970): The first Kei 4WD off-road vehicle, inspired by the Hope Star ON 4WD concept.

• Honda Z (1970): A sporty hatchback with an optional high-performance version.

• Mazda Chantez (1972): Known for its long 2,200mm wheelbase, it became a standout in its class.

Conclusion

From its humble beginnings to becoming a cultural phenomenon, Japan’s Kei car industry has experienced a remarkable evolution. The combination of innovation, practicality, and regulatory adaptation has solidified its place in automotive history. Stay tuned for Part 2, where we delve deeper into the continued development of Kei cars during the 1970s and beyond.