ORIGINAL: jrm1900

Here you go, Top Speed Calculator:
http://www.mysportscar.com/tools/topspeed.htm

Transmission Ratios 2005+Mustang (Tremec 3650) Manual
1- 3.34:1
2- 2.00:1
3- 1.32:1
4- 1.00:1
5- 0.68:1
reverse- 3.38:1

2005+ Mustang (5R55S) Auto
1- 3.25:1
2- 2.44:1
3- 1.55:1
4- 1.00:1
5- 0.75:1
reverse- 3.07:1

Then for example using 285/40 R18 tires we’ll have the following theoretical speeds in 5th gear @ 6000rpm (Manual Transmission)

3.31 = 213.93 MPH
3.55 = 199.47 MPH
3.73 = 189.85 MPH
3.90 = 181.57 MPH
4.10 = 171.71 MPH

ORIGINAL: ohnoesaz

EEk. I can't live with that. That means 90mph at like 3600rpm. imagine driving 6 hours from to Vegas like that! No gears for me. I like the idea of drive shafts though...