Which cars have all-wheel drive as a feature that's in play only when needed for traction and not otherwise?
More than 60 cars offer all-wheel (or four-wheel) drive for 2013, but the only one we are aware of that has selectable all-wheel drive is the Mitsubishi Lancer SE. A console switch lets you choose front-wheel drive, an "on-demand" all-wheel-drive mode that sends power to all wheels when needed or all-wheel-drive lock, which keeps the system engaged in a 50/50 power split between front and rear.
There may be others with selectable all-wheel drive, but the preponderance of all-wheel-drive cars (and we specifically mean cars, not SUVs or trucks) have systems that automatically engage all-wheel drive in slippery conditions and disengage it when traction stabilizes.
These systems operate somewhat differently, depending on manufacturer and model, but the common thread is that the driver doesn't decide when to activate all-wheel drive. Some systems send all the power to either the front or rear wheels in dry conditions, while others (such as Subaru's) send at least a small amount of power to the rear wheels all the time. In both cases, if either drive wheel starts to slip, some power temporarily goes to the other axle until traction stabilizes.
Selectable all-wheel drive/four-wheel drive is more common on SUVs, such as the Ford Explorer, Jeep Grand Cherokee and Toyota RAV4.
- Expert Review: 2013 Mitsubishi Lancer (Cars.com)