A vehicle has a vehicle body and a vehicle suspension system supporting the vehicle body. The vehicle suspension has a gas spring, and includes a cylinder, a rod, and an accumulator. The cylinder has a longitudinal axis. The rod is partially disposed within the cylinder and is movable relative to the cylinder along the longitudinal axis of the cylinder. The rod and cylinder together at least partially define a chamber having a variable volume that receives a first pressurized gas. The accumulator is in communication with the chamber and contains a second pressurized gas held at a threshold pressure creating a first spring rate opposing relative movement between the rod and cylinder when the first pressurized gas within the chamber is pressurized below the threshold pressure and a second spring rate when the first pressurized gas within the chamber is pressurized above the threshold pressure.