For a time, Japanese supercars had a restriction in horsepower

Explanation

This restriction was a limit of 276 horsepower (280 metric horsepower/PS) and was implemented in 1989. This informal pact, known as the Gentleman's Agreement, was established by the Japan Automobile Manufacturers Association to prevent the automotive arms race as well as curb accidents on Japan's narrow roads. The agreement was officially broken in October 2004 when Honda introduced the Legend (sold as the Acura RL in the US), which was rated at 300 hp.