I was watching Daytona 500 and one or 2 of the cars were steaming a little at one point. 1- One of the announcers said not much air is getting in since they are drafting ... I can understand this one. 2- Later another guy said they tape off the grill or parts of it to go faster. Is this for aerodynamics or for keeping the engine hot? it kind of contradicts #1 3- Later they said the temperatures are dropping so the cars would be able to go faster. Does this have to do with tires and the track and/or increased amount of oxygen? otherwise colder air is denser if we are talking aerodynamics and cooler engine temps (if any and/or significant) contradicts #2. I can't connect some of the dots. Please help!