How many and which wheels drive your car is just one of the factors to consider when you're planning a purchase. If it becomes the last point of decision between two cars, however, it can be confusing. Both front-wheel drive and all-wheel drive promise traction in slippery conditions, but not necessarily for the same reasons.
The strength of front-wheel drive (FWD) for driving on ice or snow is that the weight of the engine is over the front axle, and the wheels on that axle are handling both traction and steering. The weight gives them the best chance of maintaining a grip on the road and sustaining those functions. The other great thing is that it's really about traction --- pulling the car over the road rather than pushing it as in rear-wheel drive. Some performance purists contend that the weight over the steering spoils handling.
Though the A stands for "all," it's not all the time. On a dry, easy road, an all-wheel drive (AWD) car operates like FWD --- the front wheels both drawing the car along and steering it. It's when the car's sensors detect some slippage that they'll kick on the transaxle and put some helpful power into one or both of the back wheels. Because the driver doesn't control the use of the back wheels, and they may kick on in a tight turn, AWD does burn more fuel.
For most drivers in most conditions, there's little enough difference between FWD and AWD that other features of the car are going to make the decision. If the availability of help from the rear wheels gives you enough additional confidence to account for the gas costs, go a little safer with AWD. Remember, too, when you get into snow or ice with either drive system, that they make a difference in moving rather than stopping, and in traction rather than plowing through deep, loose surfaces.
