If tyre pressure is too high, then less of the tyre touches the ground. As a consequence, your car will bounce around on the road. And when your tyres are bouncing instead of firmly planted on the road, traction suffers and so do your stopping distances. You'll also feel a decrease in ride comfort.
It is a common misconception that overinflating your tyres will provide more responsive handling and greater fuel efficiency. In fact, over-inflation is detrimental to the tyres and can be dangerous. For the best handling and fuel efficiency, you should adhere to the manufacturer's optimum tyre pressure.

John

Silver 2005 S1 Roadster V6 - Henrietta