The Discovery Channel show Mean Machines returned last week for its third season with a new twist - the show is now called Mean Green Machines. The challenge is to see if eco friendly vehicles can measure up to not-so-green power vehicles in strength, speed and construction. The show compares the speed, endurance and power of regular drag bikes, ATVs, SUVs and helicopters to their environmentally friendlier equivalents in a 10-part series the network claims "could determine what we all want to drive in the future."

Tonight's episode titled "Smart Kart Smack Down" will follow a mechanical engineering team's effort to build a race kart with an electric engine that, if successful, wll be able to compete head-to-head in a race against a 4 Stroke single cylinder Class Kart. The plot twist is though the karts appear to be quite different, they share the same engine, unbeknownst to the gas kart race team.

If you live in Canada or have satellite television, be sure to tune in to Mean Green Machines tonight to find out if the green kart can hold its own against the proven track record of the Class Kart.

» Discover Channel