Enter "Lyn Wins" as a name to enable cheat mode.
Then, enter one of the following codes.

Effect                     Code 	
-----------------------------------------
Empty tank               - [Alt] + V
Toggle overtorque        - [Alt] + T
Refill tank              - [Shift] + V
Toggle terrain following - [Ctrl] + T
Increase speed (*)       - [Shift] + [Alt] + [Tab] + [Ctrl] 
                           then repeatedly press [Tab]

(*)Disable overtorque before enabling this code.