After SSJ was introduced, Kaioken became less proeminent. The first time Goku uses Kaioken is when he fights Nappa. Actually, there are "power-up levels" of Kaioken, and, ...

The SSJ's unit became the most powerful engine ever fitted into an American road car, a feat equaled by Mercury's Super Marauder V8 in 1958 and exceeded as late as the 1960s.