Ramp travel index or RTI, is a way of measuring a vehicles ability to flex its suspension. The rating is used mainly in the off-roading industry to test the limits of modified vehicles. The ramps vary between 15-30 degrees of angle for the vehicle to ride up. "Ramping" a vehicle involves putting one tire on the ramp and driving up slowly until one of the other three tires (usually the rear one on the same side as the tire driving) begins to leave the ground. The measurement is only taken when the other three tires are still on the ground. The distance traveled up the ramp is then measured and is divided by the vehicles wheelbase and finally multiplied by 1000 to give a final RTI score. A very good RTI score is 1000, while many vehicles have the ability to far exceed that.
