Ramp Travel Index
RTI is a way of measuring your vehicle's ability to flex.
It is measured by how far up a ramp (standard is 20 degrees) the vehicle can go while still keeping all four tires in contact with the surface underneath. Variables such as vehicle length, suspension, and so on are compensated for by using the following equations:
The number of inches a vehicle travels up the ramp before running out of suspension travel (when a tire leaves the ground), divided by it's wheelbase. Then multiply that figure by 1000.
A perfect score would be 1000, that is, the vehicle can go as far up the ramp as its wheelbase without lifting a tire. Stock vehicles do not do this, but modified rigs can reach and exceed that depending on how much customizing has been done. To compensate for extreme machines, a 23-degree and even a 30-degree ramp have been used. The calculations are the same, just be sure to mention which standards you're using when you brag.
Simplified: Inches Traveled divided by Wheelbase, multiply by 1000, equals RTI
Click here to see how NOT to calculate RTI
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