[04silverzx3]

theres nothing wrong with using your engine compression for braking while going down a hill. downshifting without rev matching will wear your clutch disc more because of the abrupt change in speeds from the engine and the tranny, but there is no more strain on the driveline from using engine compression to brake, not only that but in that situation the injectors are turned off so you arent using any fuel. not only that but if you go down a hill riding your brakes they heat up quite a bit, both the pad and the rotor. and once you come to a stop your pads clamp down onto the rotors which actually leads to warping them so in fact by using engine braking you are saving your brakes and also saving fuel.