What Turns Your Vehicle’s Wheels?
Is your vehicle front-wheel drive, rear-wheel drive, all-wheel drive, or four-wheel drive? Here’s how those wheel options work when they face snow, ice, and rain on the road:
Front-wheel drive (FWD) – Engine power is channeled to the front wheels to propel the vehicle. FWD is the most popular and prevalent system in the market because its compact setup enhances fuel efficiency and frees up more room inside the vehicle. Plus, the weight of the powertrain is concentrated over the driving wheels, so it offers good traction when it’s slippery.
Rear-wheel drive (RWD) – As the name implies, engine power is sent to the rear wheels to propel the vehicle. In passenger cars, RWD reigned until the advent of FWD in the early 1980s. But RWD can more effectively handle higher engine power and higher vehicle weights, which is why it’s still favored in large trucks, larger performance vehicles, purpose-built race cars and law-enforcement pursuit use.
All-wheel drive (AWD) – Don’t confuse all-wheel drive with four-wheel drive. Both engage all four wheels, but they’re designed and operate differently. Generally, an AWD drivetrain operates as a FWD or RWD system – most are FWD.
Power is transferred automatically via a single-speed transfer case. (A transfer case connects to the transmission to split power between the front and rear wheels.) The beauty of AWD is no driver effort is needed to activate the system.
AWD scores high with buyers who want excellent on-road capabilities with the added traction on grass, mud, sand or gravel in light, off-road conditions where a front- or rear-wheel-drive vehicle may get stuck.
Four-wheel drive (4WD or 4×4) – Four-wheel drive typically features a two-speed transfer case with high and low ranges for maximum traction. 4WD vehicles typically operate in RWD until four-wheel traction is required; and while most systems are driver-activated, many offer a setting that automatically engages the high range when it’s slippery. The driver must still engage the low range.
Found in large, rear-wheel-drive trucks and larger SUVs with additional ground clearance compared to passenger cars and crossovers, 4×4 still provides the best traction and capability in off-road conditions.