Really curious as to what the solenoid actually does with the intake cam characteristics. From my understanding of VVTi systems, it won't increase lift of the valves. So it has to be a change in the profile with duration. Wonder what the impact is on fuel economy.
As an aside, when I had the Dinan Stage 2 tune installed in my BMW 135i, not only did I get increased HP/torque but I also got better fuel economy under normal driving conditions. What I observed was about a 3 to 4 MPG increase per tank full of gas with my mixed driving. Wonder if this solenoid modification will produce similar results.