Most those who run at Bonneville looking to make the 200+ MPH club can contest there is a big difference between 150 and 200 MPH. It's part of the reason why NHRA mandates parachute starting at 150. Not only power requirements. But air flow becomes far more critical. And of course. More dangerous. Even today's designs that have the airflow requirements Autocad into the body/chassis and suspension design do so with warning of 200 MPH. The physics of hi speed driving change rapidly starting at 150 MPH.