This week at TreeHugger: The 2/4SIGHT V6 prototype engine can switch between 2-stroke and 4-stroke modes, giving a 2.1-liter the power of a 3 or 4-liter engine. Benjamin Nelson shows his DIY all-electric motorcycle, getting the equivalent of 300 mpg. This one is weird, but kind of cool: the CVO8 robot eats suburban sprawl and leaves flora behind. Finally, the advanced Luxim plasma light bulb is twice as efficient as high-end LEDs and lasts 20,000 hours.

Researchers in the UK have developed a new kind of engine. It could be called a hybrid, but what it combines is not two power sources but rather two modes of operation: 2-stroke and 4-stroke. The goal is to be able to significantly downsize the engine and get the fuel economy benefits of smaller displacement, but to be able to switch seamlessly to 2-stroke mode when more power is required at high loads and low speeds.

"I bought an 8hp Briggs & Stratton ETEK motor used through Craigslist," said Benjamin Nelson. "Then I mounted the motor to the frame using the existing engine mounting holes and a piece of scrap aluminum plate. I found a sprocket and chain in the tractor repair isle of the farm store. If gas is three bucks a gallon, I can go 300 miles on that same amount of electricity. 300mpg isn't too bad for a motorcycle, is it?"

Plain surreal: "Lastly, the rear legs of the CV08 will serve as a means of power-collection: they pull chubby Australian suburbanite stragglers up into a liposuction chamber, which draws out all of their excess fat [which then powers the CV08]. The now trim Aussies are then shot out of the backside [read: ass] of the robot, parachuting down to safety—along with a brand new bicycle constructed from recycled suburbs.

At 140 lumens/watt, these pill-sized plasma light bulbs by Luxim are a pretty awesome contender for "light of the future." They are almost 10 times more efficient than traditional incandescent light bulbs, twice as efficient as current high-end LEDs, and they also beat CFLs, most of which are around 50-80 lumens/watt. Only the prototype 300 lumens/watt nanocrystal-coated LEDs can hold a candle to them.


TreeHugger's EcoModo column appears every Tuesday on Gizmodo.