Specialist?
Wot, so you are going to get nice linear speed to RPM ratio's in real life are you?
The car will go at 220 mph at 10.5k revs in 5th? don't think so!
The car will go at 20 mph at 1k revs in 5th? Don't think so!
Maybe you should learn some basic physics, oh and learn not use the crappy default graph settings in excel.

Your graph is about as accurate as my Nan's eyesight!

The only thing "specialist" about this is maybe a "special" person who sits licking the window in a sunshine bus made it!