Well, I'm going to make an estimate on this one...
I was driving my '93 Buick LeSabre down the toll road in Indiana. Now, the speedometer only goes to 85, however there's still 2 inches left between the pedal and floor at this point. I got up to 85 and then, being 17, I decided it would be a good idea to go ahead and floor it. When the pedal hit the floor, and I had accelerated all I could the needle was straight down(I could only see the tail end of it sticking up, the normal indicator part was buried). Now I'm sure it gets inaccurate after 85, but I'd say I was doing atleast 105, if not 110 or more. I know 110 isn't that exciting for most of you, but consider the fact that it was a shitty Buick LeSabre, and a 4 cylendar at that, I'd say that's pretty good. After a min or two of this I started getting paranoid so I backed it back down to 70ish and, what do you know, after the next rise there were 4 state troopers in the median trying to catch speeders.