Ok so a lot of back and forth is happening within this thread. The OP originally stated how frame rate affects vehicle speed, and I think that this is well known. While I do not believe any super car should be nerfed, I have an issue with people stating that the PD vehicles are overpowered. While I do believe that the cruiser (Crown Vic) goes faster than IRL, interceptor and Buffalo (Charger) speeds are severely unrealistic. One simple way to fix this issue is to bring back a PD division that was mentioned before. As an active member of PD, and member of TED, I can tell you all that the Traffic Enforcement Division is a wasteland of potential. If you were to limit Buffalo usage to only Traffic Enforcement and increase its speed cap to its legitimate speed (240 km/h instead of 185 km/h) and decrease the cruiser to its realistic speed (205 km/h) there would be more realism within pursuits (given there are TED units on duty). With that being said, people want to talk realism but then take drags on a mountain hike to flee from police. I think most of these pursuit issues can be resolved in game with more realism in RP. Its all a matter of perspective for everyone within this thread. Here are some IRL km/h statistics for you all to compare to server side mechanics:
Porsche 911 = ~300 km/h
Dodge Charger (Buffalo) = ~240 km/h
Ford Interceptor (SUV for modded players) = ~210 km/h
Ford Crown Victoria (Cruiser) = ~200 km/h