Mr Bennett estimates an LPG saving of one to two per cent which, if replicated on a commercial scale, could mean massively reduced energy usage and bills.
For a while, Mr Bennett thought he'd cracked it. However, like many a backyard invention, it had the tendency to be temperamental.
"It wasn't exactly the eureka moment I was hoping for," he said.
"So I won't be solving the world's energy crisis just yet."
It's not a new idea - Mr Bennett was inspired by a YouTube video which showed an experiment in America of a similar concept. But his challenge was to try to make it more realistic and feasible.
He said the money in big creative think tanks was staggering, but that did not mean that backyard inventors could not themselves come up solutions to the world energy crisis.
"Look at this, I'm using a bloody plastic lunchbox," he said, as he gestured towards his contraption. Mr Bennett said one of the group has invested about $4000 so far on a Tesla quantum generator - basically, harnessing energy from the cosmos (lightning, etc).
"He's waiting on bits to come from China.
"It's potentially capable of generating 10 kilowatts."
Another member has patented a system using wheels which is designed to help load a digger onto a truck.
The Whangarei Inventors' Club meets on the second Wednesday of each month at 7pm, at Fabrite Sheet Metals, Fraser St.