They’re generally more prone to damage compared to simpler Part-Time 4WD systems and more expensive compared to regular Full-Time 4WD systems. 4WD is generally accepted as a car or more typically a larger SUV (Sports Utility Vehicle) that uses a driver selectable system that mechanically engages the drive to all four wheels. Road & Track participates in various affiliate marketing programs, which means we may get paid commissions on editorially chosen products purchased through our links to retailer sites. Wheel slip results when the torque applied to a tire exceeds its available traction (often, at red-light drag races). Of course, there are lots of different types of all- and four-wheel drive systems that buck these conventions. Overall, a rear-drive-based car or truck benefits the most from the added traction a good 4WD system provides, given the configuration’s inherent tendency to slip and slide over slick roads. But this isn’t a “Potato” “Po-tah-to” situation, and they aren’t the same thing. This means that in the unexpected situation where the corner is more slippery than expected or when immediate traction is required to move safely into merging traffic, All-Wheel Drive is already engaged and the required level of traction is available to safely negotiate the situation. If you buy from a link, we may earn a commission. 2019 Toyota Prius AWD-e First Drive: Can A Prius Be Fun? 4WD is normally used on large SUV Four-Wheel Drive (4x4) vehicles designed to use the extra traction of 4WD in off road situations. Today, nearly a third of all vehicles sold in the U.S. put their power to the pavement via all four wheels, employing either four-wheel drive (4WD) or all-wheel drive (AWD) as traction-enhancing alternatives. Getting moving in these cases involves a sore back until both wheels on the axle gain traction again. However, unlike 4WD cars, AWD is always engaged and provides varying amounts of power to the axles depending on traction conditions. What is the difference between an All-Wheel Drive (AWD) car and a Four-Wheel Drive (4WD) car? These vehicles are designed for normal, everyday driving on the roads when weather conditions or minor hazards might create slippery road conditions. If you live in an area that gets a lot of snow you might want to consider a vehicle with AWD or 4WD. Some all-wheel drive … Full-Time 4WD Multi-Mode systems can operate in Full-Time 4WD mode, just like other Full-Time 4WD systems. Whichever tire has the most traction is guaranteed to get the power it needs, helping prevent the vehicle from getting stuck. This technology leverages the same sensors used by anti-lock braking systems to measure wheel speed and determine whether any wheel under power has lost traction. Our car experts choose every product we feature. (Today, this is an oversimplification for most new cars driving off of the lot, but we’ll go with it for clarity’s sake.) With a limited slip differential, the mechanism works like a conventional differential during turns, but solves the problem of slipping by transferring more torque to the non-slipping wheel. Fuel economy naturally takes a hit, and there is inherent wear on the drivetrain. the wheel that’s not slipping) to provide grip on poor roads, and it works in the background without any input from the driver. You may be able to find the same content in another format, or you may be able to find more information, at their web site. Our recent experience with Toyota’s entire cross-over and SUV lineup in Breckenridge made it abundantly clear that competent drivers armed with even basic AWD can comfortably navigate less-than-ideal road conditions — and we didn’t even follow a cardinal rule of using snow tires.