Forum:How you count top speed of a vehicle and count height in GTA:SA?

How you count height and vehicle speed? I see in Rancher article, there says, the vehicle top speed is 157 km/h. How you can count speed? and also, in Mount Chilliad Article, there says, This is the tallest feature in San Andreas, with 2000 ft tall. how you count it? Parachute and Helocopter, AFAIK, only shown bars. Help me!