Silicon Valley spawned the technology revolution. But turning the tables on Detroit to design a car with revolutionary gas mileage is a challenge 100 times greater, says Ray Lane, managing partner at Kleiner Perkins Caufield Byers.

“It’s a huge problem to deal with,” he said at the AlwaysOn Going Green conference Tuesday.

Difficulties aside, several startups at the conference boasted that they were up to the task. Among them were:

Commuter Cars: designers of the miniature Tango, a boxy electric vehicle about half as wide as the Smart car and capable of 80 miles between charges.

Transonic Combustion: makers of a fuel injection system to improve the efficiency of gas engines. The company’s hope is to demo a car by the end of the year capable of 100 mpg at 50 mph.

Venture Vehicles: creators of the VentureOne, a three-wheel wedge of a car with the front wheel larger than the rear two. The vehicle anticipates up to 85 miles a gallon and is to reach the market by 2010.

EcoMotors International: builders of a diesel engine aimed at achieving 100 mpg by 2010.

By Mark Boslet, Editor at Large.