What should my pressure be? Make Model Spec SL. 20 OPTSL55. 5.4 V8 AMGSL55. 5.4 V8 AMG. 19 OPTSL55. 5.4 V8 AMG. BASESL55. AMG BASE OPTSL63 AMG. 6.2 V8SL65 AMG.SL65. AMG