An F1 car's top speed is dependent on the downforce levels it carries, which in turn depend on a) the lenght of the striaghts and b) the existence or not of fast turns. Monza has the lowest downforce levels of the whole calendar but there is still a huge amount of downforce by sportscars standards. If a car was to be stripped of its downforce (like in the Honda experiment) top speeds would be much higher than they now are. A super-long straight would neccessitate such a set up, hence my reference to that 5 km vastness. 


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FERRARI RULES!!!