I've used this on at least 5 different vehicles. A quick wash of the engine compartment with a light degreaser (Simple Green), fast rinse and then spray with Shine All. Every mechanic who pops the hood stares at the engine for a minute or two and compliments me. I typically do this twice a year (more, depending on milage driven). No harm to fittings, decals, hoses or electric/electronic connections or filters. Simple to use with great results!