Scion xB Tokico HP Series Shocks and Struts the famous "Blue Shock" - continues to be the overwhelming choice of performance enthusiasts looking for the best in overall handling and ride quality. The HP Series damping typifies TOKICO's valving flexibility and philosophy by minimizing low speed damping force and greatly increasing damping at medium and high piston speeds for improved compliance, tire adhesion and handling.

Gas-pressurized xB HP shocks have been available for over 30 years and like non-pressurized shocks, they use shock oil as a damping medium.

In a gas-pressurized design, the oil inside the xB HP shock body is pressurized to minimize the negative effects of foaming or cavitation. For maximum performance, the xB HP shock piston must work in clear oil. Oil naturally has some air bound up in solution. When the xB HP shock's piston moves through the oil, a pressure drop is created behind the piston, which permits air to come out of solution, so oil foaming occurs. By maintaining gas pressure on the oil, foaming is reduced.

There are two types of xB gas-pressurized shocks, xB HP monotube high-pressure and xB HP twin-tube low-pressure. Generally, a twin-tube low-pressure xB shock provides a better ride for a given level of control compared to a monotube high-pressure style.