A kei car can go anywhere from around 60 to 85 mph, though it is most comfortable and recommended to drive them at 50–60 mph. While they can reach higher speeds, it puts significant stress on the engine and is not ideal for sustained driving.
The main drawbacks of owning a kei car are safety concerns due to their small size, performance limitations like a lack of power, and difficulties with maintenance, parts sourcing, and registration, especially in countries like the United States. They are often not suitable for highway driving and may have poor sound insulation, lack modern features, and be top-heavy.
Safety and performance Safety: Kei cars are more vulnerable in crashes with larger vehicles. Many imported models are old and lack modern safety features, and their compact size increases the risk in front-end collisions. They can also be top-heavy, making them prone to rolling over. Underpowered: Engines are typically limited to $660$cc and \(63\) horsepower, making them feel slow and underpowered, especially on hills. Poor handling: Some models have a lack of responsiveness, with body roll, and can feel unstable, particularly in the rear end in wet conditions. Highway limitations: Their small size and lack of power make them unsuitable for extensive highway driving.