The ‘Gentleman's Agreement’: Japanese cars limited to 180 km/h and 280 hp?
Created by Tiago Fernandes at Thursday, 27 February 2025
For several decades, Japanese sports cars have been recognised for their performance, but also for two peculiar limitations: a top speed of 180 km/h and a declared power of 280 hp. These restrictions were the result of a ‘Gentlemen's Agreement’ between Japanese car manufacturers, implemented as an attempt to reduce road accidents and avoid stricter government regulations.
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Origin of the Gentlemen's Agreement
In the 1980s and 1990s, Japan experienced exponential growth in the production of high-performance cars. Models such as the Nissan Skyline GT-R, Mazda RX-7, Toyota Supra and Mitsubishi Lancer Evolution reached high power levels, which raised concerns about road safety and led manufacturers to take preventative measures.
To avoid more severe legal impositions, the Japanese brands voluntarily agreed to limit the power of their vehicles to 280bhp and the maximum speed to 180 km/h, setting an unofficial standard.
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How did the 180 km/h limit and 280 hp work?
Cars began to include electronic limiters that prevented them from exceeding 180 kilometres per hour. However, this limitation could be removed by modifying the ECU (Engine Control Unit).
The advertised power of 280bhp didn't reflect reality either. Many models exceeded this figure without mechanical modifications, as demonstrated in independent tests.
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Examples of cars that exceeded 280bhp
Toyota Supra MK4 (2JZ-GTE) - Officially 280bhp, but the European and American versions reached 320bhp.
Nissan Skyline GT-R R34 (RB26DETT) - Announced with 280bhp, but in practice produced more than 320bhp.
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Does the agreement still apply today?
With the globalisation of the car industry, Japanese brands began to abandon the limits of power and speed. The first model to break the rule was the 2004 Honda Legend, announced with 300bhp.
Models such as the Nissan GT-R R35 (485bhp) and the Lexus LFA (560bhp) marked the definitive end of the agreement, allowing Japanese super sports cars to compete globally without voluntary restrictions.
Photo: Muhammad Mu'tasim
