I lean towards what 300D-91 says - for the best mpg, cut the manifold signal the ALDA. As for the Cummins, maybe it was set to 7 psi from 12 psi.

I don't choose to run boost at cruise speed, it just happens. I see at least 5 psi at 70 mph. Did Dave/gsxr really say it's normal to see no boost at 70 mph or did he say it's normal to see no boost when there's no load on the engine? A W124 at 70 mph isn't slicing through air. That engine is working. I understand what I see with my mechanical system but EDS isn't necessarily as straightforward. It could be that EDS is tuned for economy and, pardon my use of the word, artificially reduces boost under steady load and rpm conditions. The beauty of EDS in place of a mechanical system is that it can dynamically switch from economy mode to power mode... when it works. Maybe Hermann Göring was referring to EDS when he made his comment about the state of German technology.

Which begs the question of those who've converted from EDS to mechanical wastegate control - what's the effect on mpg?

Sixto
87 300D