Correction: The original version of this piece incorrectly stated that, according to Koomey’s Law, the amount of electricity needed to run a computer is halved each year. In fact, the law states that it is halved every 18 months. This version has been corrected.

Kevin Freiberg, Jackie Freiberg and Dain Dunston are co-authors of the book “Nanovation: How a Little Car Can Teach the World to Think Big & Act Bold.”

In 1900, it wasn’t obvious that we needed a replacement for horses.

After all, horses were all-terrain vehicles that got the job done. So, when car’s arrived, they were greeted with far less fanfare than, say, the iPad, and were all but dismissed as dirty, noisy and unnecessary.

The shift to computers was much the same. When the machines first started hitting desktops, everyone knew at least one writer who turned up their nose and treated the phrase “word processor” like a four-letter word. These are likely the same writers who are madly texting their grandkids on their smart phones today. Paradigm shifts are like that. They’re hard to see until they’re past you, and even harder to lead.

Given this, you probably haven’t noticed we’re in the middle of just such a shift today.

Cover of the book “Nanovation: How a Little Car Can Teach the World to Think Big & Act Bold” by Kevin and Jackie Freiberg and Dain Dunston.

It’s well known that the line between computers and cars is blurring. Our cars require complex diagnostic checks, make phone calls, and communicate with satellites. But, even with all of these new technological bells and whistles, our cars are still not 100-percent emission free. So, how can America best position itself to lead the clean-vehicle-technology paradigm shift? We studied the Nano — a real car built by Tata Motors that sells in India for $2,100 — to find out. Based on our findings, we see three key steps individuals and the nation need to take.

1. Question the unquestionable.

Questioning the unquestionable can lead to a game-changing solution. For example, when the makers of the Nano saw entire families riding—and crashing—motor scooters in India, they didn’t ask if it was possible to ban scooters. Instead, they asked, “How can we build a safe car that sells for the price of a motor scooter?” It was an audacious question that redefined the problem, and it was a goal industry experts had deemed unachievable.

Fuel efficiency makes sense. It reduces emissions, lowers consumer costs and helps reduce dependence on foreign oil. But about 80 percent of the energy you put in your gas tank goes unused. Engineers like David Foster at the University of Wisconsin are working on improving that, but they have only shown incremental improvements on that percentage. What if we had settled for only an incremental improvement in nuclear technology? The World War II history books would look very different. We need a Manhattan Project for fuel efficiency. An undertaking of this magnitude could significantly increase the amount of energy squeezed from a gallon of fuel.

2. Do more with less.

Less is only more when it’s better. Take Wal-Mart, for example. The company’s success is based on wringing every unnecessary cost out of the supply chain. Team Nano’s goal was even more ambitious: to take 70 percent of the cost out of every part and sub-system in the car. Suppliers got in on the act, too—from Germany’s Bosch to America’s GE, Delphi, TRW and Visteon. Together, they discovered that enforcing elegant design made everything in the car lighter, stronger and cheaper.

This resulted in a new paradigm in car development and manufacturing: The horsepower wars are over and the smart wars are beginning. Lighter vehicles use less fuel, and lighter vehicles that capture more energy from a gallon of gas use even less. Land Rover, also owned by Tata Motors, just announced they’ll take 1,100 pounds out of their top-of-the-line Range Rover without reducing interior space. The lessons learned while taking weight and cost out of the world’s cheapest car let them do the same with one of the world’s most expensive.

3. Go to the tntersection of trends.

Getting 50 percent (or more) efficiency out of a gallon of fuel is beyond the capability of current technology. But think of the rate of technological change in the quarter century from the first Apple computer to the end of the Internet bubble in 2000. Then, think of the change in the eleven years since. We’ve gone through more than a quarter century of change in a decade and the changes of the next decade will dwarf the changes we’ve seen since the first PC. Most people know about Moore’s Law, which says that computing power doubsles every 18 to 24 months.

Now, meet Koomey’s Law, named after Dr. Jon Koomey of Stanford University, which says the amount of electricity needed to run a computer is halved every 18 months. Project that forward a decade.

Can automotive engine efficiency increase that quickly? Not yet, but that doesn’t mean the rates of change won’t still be geometric. This is a critical decade for innovation in general, but particularly when it comes to cleaning up our cars’ emissions. It will require doing more with less, and it starts with gutsy leaders willing to boldly acknowledge the oncoming paradigm shift rather than settle for the status quo.