Smiles per hour: The Japanese Kei to success

We live in a world in which standard family estate cars can boast 500bhp or more and SUVs can often do 160mph. Thank heavens, therefore, for a class of vehicle which, although strictly limited on size, weight and horsepower, can offer huge driver thrills in return. If smiles per hour were a measurement, then the diminutive ‘Kei’ class of vehicles from Japan and, in particular those produced in the 1990s, must surely be world leaders.

The Kei class of vehicles came out of a post-war Japan with the aim of mobilising the population through small, efficient and economically priced vehicles. While full-sized automobiles were heavily taxed, the government made allowances for vehicles of less than 2.8 metres in length with engines of under 150cc, which gave rise to a slew of small, ingeniously packaged vehicles which, though modest in size, were able to get the country moving. 

Although the maximum permitted engine size and length grew to 360cc and three metres - in 1951 to 550cc and 3.2 metres in 1976 - at this point, the Kei were seen as being too small and too slow to be of much appeal to foreign buyers and they remained largely under the radar outside of the home market.

This all changed on 1st January 1990 when engine capacity was increased to 660cc. At around the same time that the first wave of turbocharging fever had hit its peak and, almost immediately, with the aid of the latest induction technology, Kei Cars became fun.

One of the leaders of the new wave of high-performance pocket rockets was the Daihatsu Mira TR-XX. Based on the Cuore hatchback, this pint-sized city car boasted a fuel-injected turbocharged, intercooled three-cylinder engine. It was even offered with full-time, four-wheel-drive as the X-4.

The Mira was also easy to tune, practical and capable of embarrassing traditional hot hatchbacks of twice its size. Although Kei class cars had a suggested power limit of 64bhp, this was something of a gentleman’s agreement between the manufacturers, and most would easily exceed this as they left the factory. With even simple modifications, huge power gains were possible for the most basic home mechanic.

Honda was keen to be a part of the pocket rocket action. It already had prior form at producing tiny sportcars and in 1991 it launched the BEAT. A mid-engined, two-seater roadster, the tiny BEAT was a triumph of engineering. Honda eschewed the trend for turbocharging, and instead produced a 660cc triple which, thanks to trick valves and individual throttle bodies for each cylinder, was able to rev cleanly to more than 9500rpm, while sounding exactly like a miniature V12 as it did so. With handling to match its peppy performance and a zebra print interior, the Honda became an instant cult classic.

Last but not least in the trio of Kei-oddities, is the Autozam AZ1. Launched by Mazda under its sub-brand, it took the idea of a sporting Kei Car to another level. With a turbocharged, intercooled triple cylinder engine from Suzuki mounted amidships, not only did this tiny coupe look exactly like a miniature Ford RS200 rally car, it also boasted gullwing doors. While it was immediately famed for its sublime handling and the strong performance from the raucous engine, the AZ1 was launched in the middle of a recession and subsequently failed to find many buyers at the time, leading to production being cancelled just a year later.

Today, these sporty Japanese miniatures have become fast appreciating modern classics. With reliability, rarity, and with a huge ability to engage a keen driver, these punchy little toys are increasingly seen as the antidote to unusably powerful sportcars, thanks to their ability to be driven flat out… all of the time. Even better, with a Flex policy from Footman James, they can be insured alongside other classics resulting in just one premium and one renewal date for your entire garage of moderns and classics.

Do you own one of these cars, or have you always wanted to have a go in one? Let us know your thoughts in the comments below.