Fuel Smart, Variable Displacement, Snake Oil?

This was recently recommended to me. www.fuelsmart.info
Claims: Our patent-pending microprocessor-controlled system monitors vehicle performance and selectively shuts off cylinders when it detects conditions that do not require maximum performance. In addition, our new system is equipped with sensors not currently used by auto manufacturers for even better monitoring and responsiveness.

I know the hive mind is smarter than just I. Is this real or is this snake oil?
Seems that it shuts off fuel injectors to save fuel but will this hurt long term reliability?
Naturally, I am skeptical and the website does not give enough to dispel my skepticism.

Real premise but sounds like vaporware.

Tom Suddard wrote: Real premise but sounds like vaporware.

Yup.

Variable displacement is pretty old (GM did it rather famouly for Caddilac, but I know it's been active for 20 years...). Hard to get it to work really well.

And the best systems not only cut the fuel, they also cut the valvetrain- which is much better than letting the "off" cylinders to just keep pumping.

Just turning off some of the injectors will cause a lot of intereting side effects. Most of them not worth doing.