Today’s SUV shoppers have more choices than ever unless they’re shopping for a four-wheel-drive SUV (4WD). While 4WD enjoyed decades of popularity as the drivetrain of choice for off-road capable body-on-frame SUV models, all-wheel-drive SUV models are taking over. So, what is 4WD? How is it different than AWD?
What’s the difference between 4WD and AWD?
First, consider that all modern SUVs emanate from two design sources, cars and trucks. Automotive engineers used pickup trucks as the basis for the first popular SUV models, and newer SUV designs utilize technology derived from cars. Truck-based SUVs use a traditional front-engine, rear-drive configuration, whereas car-based SUVs built on unibody platforms use front-drive.
Truck-based body-on-frame SUVs with 4WD are becoming rare as newer car-based SUVs enjoy increasing popularity. The most significant advantage of the traditional four-wheel-drive SUV is its two-speed (high range and low range) transfer case, which disperses engine power from the transmission to the front and rear rears via driveshafts and differentials. In addition, 4WD components are usually more substantial (and heavier) than AWD system components.
On the other hand, an AWD system is always active or engages automatically whenever the vehicle’s onboard systems detect slippery conditions. Car-based SUV AWD systems begin with front-wheel drive and add a center differential to drive power to the rear wheels. So while AWD isn’t the best choice for rock crawling, it works well for “typical adverse weather conditions and tackling dirt roads,” according to Consumer Reports.
When is a 4WD SUV model better?
Some examples of truck-based SUV models offering 4WD include the Jeep Wrangler and the Toyota 4Runner. For serious off-roading, these 4WD options provide the ability to shift the transfer case into a low gear range, which makes traversing difficult off-road obstacles safer and reduces the potential for vehicle damage. Truck-based 4WD SUVs also offer increased towing and payload capacities over comparable car-based AWD SUVs.
When is an AWD SUV model a better choice?
The Kia Telluride and Honda CR-V are popular car-based SUVs with available AWD. The most significant advantage of AWD, and the reason car-based SUVs are taking over, is its lighter weight and compact design offers increased fuel efficiency and better space utilization. As stated, AWD isn’t as strong as traditional 4WD but is strong enough to provide traction when needed. An AWD SUV is a good choice for anyone who drives on paved streets and highways with the occasional dirt road thrown in that doesn’t need to tow or haul big loads.
The future of AWD
Hybrid electric drive systems are changing the way AWD works. In a hybrid electric system, a gas engine powers one set of wheels along with help from an electric motor, while another electric motor delivers power directly to the other set of wheels. All electric AWD systems often drive each wheel independently using four electric motors. These systems eliminate weight and potential maintenance items by reducing the number of driveline components. In addition, advanced electric AWD systems enable precise power delivery to each wheel for optimum torque while maintaining traction.