LOL, have to agree with you , I don't know how putting a "jet nozzle" on your exhaust pipe can lower backpressure on the IC engine.
To increase the velocity through the nozzle there has to be a drop in static pressure , so more pressure required upstream if ambient pressure is constant.
It'd be better to put a cone diffuser on the exhaust pipe as freepower engines do, heh heh , and motorcyles have been doing for decades with megaphone exhausts .
I'd like to see the actual engine dyno readouts that substantiate their claims , there ain't no "free lunches" in this world ...............the reduced fuel consumption is probably a result of "choking" the engine and reducing its power output .
I'm on two minds on this. It's been around for a while now and the newspaper article when it was released stated it sounded like it was going to suck the turbo out thru the exhaust on a truck engine used by a independent operator. It looks to create a Venturi type effect but my understanding from this group says it can't work until there is a pressure drop and injecting more to create this Venturi effect would increase pressure not drop it. It would be good if it worked