I know what it is .... Test for how to race Q3 with a broken roll bar !
I was intreged by the talk this week over top speed. Which we seem as a forum to give too much attension to, it keeps comming backup. I beleive it has to do with atleast a couple or Ferrari personnel mentioning it (I'm sure I read Alonzo mentioning a couple of times). The journalist never ask him to explain in more depth what he means.
As a statistic topspeed is a very limited in what it is telling us. To register it, you need only hit it. It doesn't say that you were at that speed for .0001 of a second or 10 seconds. WIth more downforce and lower gear ratio (everything else being equal) you'll end up with a lower top speed but you'll attain that top speed much quicker, be able to brake later, maintaining that speed longer. That doesn't only apply to long straights it would apply all over the track including high speed corners were you'll hold more speed. I suspect what Alsonzo eludes to is aero efficiancy .... and not purely topspeed. I don't know of a good statistic of aero efficiany.