PicoSpray Aims For A Fraction Of Emissions At A Fraction Of The Cost

PicoSpray’s streamlined small-engine fuel injector.

PicoSpray Aims For A Fraction Of Emissions At A Fraction Of The Cost

The small engines in scooters and motorcycles spew more greenhouse gases than those in cars and trucks 10 times their size. Replacing the carburetors in those motors with fuel injectors–already standard in larger vehicles–could cut through the smog.


Fuel injectors can reduce emissions from small engines by more than half, but they’re expensive–up to five times more so than a carburetor. The PicoSpray fuel injector cuts costs by eliminating two of three components–a simplification made possible by focusing on the single-cylinder nature of small engines. “Our design doesn’t require a separate fuel pump or a pressure regulator,” explains inventor Lihang Nong, a University of Michigan engineering grad student.

Photo by Thomas Liggett; Illustration By Peter Sucheski

1 The throttle body directs the fuel spray to the intake of the engine. The far side of the throttle body connects to an air filter.
2 The cylinder on top is the main unit. It acts as fuel pump, regulator, and injector.
3 The control unit contains sensors and circuitry that tell the injector when to deliver fuel, and how much.
4 A spring keeps the throttle closed until opened by the rider.

Both PicoSpray and its device were spun out of an academic engineering challenge. Nong and his Wolverine teammates didn’t pull off the 3,300 mpg car they set out to create, but they did found a company to develop a component that was integral to that project. When tested against traditional injectors, the startup’s model has yielded comparable gains in fuel efficiency and emissions control at half the price ($25).

Remaining Challenges:

  • Raise funds. PicoSpray paid for its launch with a grant, a microloan, and prize money from a clean-energy contest. Scaling will require deeper coffers. The company is talking to potential clients and industry experts to determine how far off profitability may be–and how much more cash it needs to raise.
  • Prep for production. The PicoSpray team ironed out major issues in the pro-totype, such as reliability at high temperatures. Now, with a patent pending, it needs a second round of more focused tests to ensure that the unit is ready to be mass produced.
  • Wait out the market. “The main [opportunity] driver is government regu-lations,” says Nong, who expects sluggish initial interest from motor-vehicle manu-facturers for a few years. After that, more stringent emissions caps will take hold in Asia. “They’ll have to go with fuel injection then. There’ll be no choice.”

The Future
Nong’s goal is to finish what large-engine makers started in the ’80s and kill off the carburetor for good. And while Asia represents the biggest potential market, Nong also plans to court lawn-mower makers in the U.S., some of whom are already buying carbon credits to sidestep regulations. Says Nong, “If this thing is low-cost enough, we could make it worth their while.”