I've been driving cars (3 Renault Fuegos and 2 Benzes) with Bosch injection systems for the last 12 years and about 1/2 million miles. Never used any additive, never ever had any problems with them. Neither did I ever replace a Bosch fuelpump on any of my cars either. This may just be luck but I doubt it. In my opinion these "fuel system cleaner" products are just marketing gimmicks. Same as the so-called "gas line antifreeze" products up here in the frozen north. Never used it never needed it. And I used to park outside.