Now that fuel-saving concept, called engine stop-start, is coming to the mainstream; and one of the first models to get it is the mid-size 2013 Ford Fusion.
The 2013 Ford Fusion will be one of the first cars from a mainstream brand to get engine stop-start (which Ford calls Auto Start-Stop). It will be offered as a $295 option on Fusion models with the 1.6-liter EcoBoost engine—which is projected to achieve 26 mpg city, 37 mpg highway.
So far, the feature is offered in only a few other vehicles. The 2012 Kia Rio remains the only other mainstream 2012 model with start-stop—and it's a feature due late in the model year, in that case. In the Rio, it's part of the Eco Package, which also includes a stronger battery.
We've experienced start-stop in models from BMW and Porsche, where the system is now widely deployed, and found them to be quite unobtrusive. Even the legendary Porsche 911 sports car is getting the system for 2013.
Mainstream automakers have had issues bringing the systems not so much because of engineering hurdles or buyer perceptions, but because U.S. EPA tests, which only include a few short stops, don't necessarily reflect the mileage improvements that commuters are likely to see. In turn, these systems costs a few hundred dollars—even to install in high volume.
But the payback you see at the pump could be significant. In real-world urban stop-and-go, expect to see an improvement of up to three to five percent from stop-start—although you could save as much as ten percent in closely spaced stoplights and the like. On average, Ford says, engine start-stop increases fuel economy by 3.5 percent; the automaker also cites a U.S. Department of Treasury study estimating that 1.9 billion gallons of extra fuel in 2011 were consumed due to traffic congestion.
In an era of four-dollar gasoline, it's an option choice that's not just green, but economically sound. So, while the payback for hybrids and their much higher sticker price doesn't always work out favorably, for anyone who commutes often in stop-and-go traffic, you could see the option cost back in just a few years.