Today i conducted some speed measurements of my tornado xp. On 16% nitro it did around 60kph (~37mph). These 2 white lines are 40meters apart. It took ~2.4 sec to reach this distance.
http://mieszkancy.ds.pg.gda.pl/~jimi/auto/warhead/

start line at 0.733 sec , finish line at 3.167 sec
On 1st gear it revs to much higher rpm than on 2nd, so using 20% nitro should add another 5kph.