The 4WD vs AWD debate and RWD vs FWD debate has been going on for years and what’s best for you depends on your finances, where you live, your lifestyle and expectations. If what everyone else is doing matters, consider this, 30 percent of all vehicles on U.S. roads will have AWD by 2015.
In your pursuit of finding the best drivetrain, you’ll want to know some auto lingo because all those WD’s have nothing to do with lubricating spray.
What are the types of drivetrains?
Rear Wheel Drive: The engine, usually in front, powers the rear wheels, which “push” the vehicle forward. Rear wheel drive is typically reserved for performance vehicles and pickups which means it is more expensive and less efficient.
Front Wheel Drive: Engine, transmission, axle-gears and differential (the gearing that allows wheels to move at different speeds when cornering) combine in a single, front-loaded unit. FWD cars are “pulled” forward and the most popular drivetrain amongst drivers. If gas mileage and value is your top priority, stick with FWD as it carries a cheaper price tag and has better fuel economy than the others.
Four Wheel Drive (4X4): In most 4WD vehicles, the driver chooses when to distribute the engine’s power evenly among all four wheels and when to engage only two (typically the rear wheels). This is known as part time 4WD. Full time 4WD is rare because it is significantly less efficient than part time 4WD systems. The 4WD transfer case lacks a differential which means the wheels have difficulty rotating at different speeds, unless the road surface—thanks to ice, snow, mud or bumps—facilitates slipping. For this reason, driving in 4WD on dry pavement can damage the drivetrain and/or the tires. You have two 4WD gears: high and low. The low option is for extreme conditions requiring high torque and minimal speed—when stuck in deep snow, for example.
All-Wheel Drive: Power in AWD vehicles are typically sent to the front tires and only when there is a lack of traction will the vehicle “split” power with the rear tires. Thus, all wheel drive vehicles are actually all wheel drive vehicles only some of the time. The split of power is typically 60 percent to the front and 40 percent to the back. Subaru and Audi, meanwhile, have a special full-time all wheel drive systems in their vehicles for a 50:50 split. AWD vehicles have somewhat less traction than their 4WD cousins and lack the low-gear option of 4WD.
For a super in-depth look at drivetrains, go here.
Where do you live?
If you live in South Florida, you may never need added traction. 4WD and AWD become more cost effective as winter driving conditions become more severe, but they are not the end-all be-all. Tires matter, big time.
If you only occasionally experience snowy or icy roads, FWD may be the best option since the engine sits right over the wheels pulling the car. RWD vehicles can struggle during inclement weather because there isn’t enough weight to help the rear tires get traction. If you’ve been around for a while, you probably remember throwing sand bags in your trunk to help your RWD car get better traction.
What are you doing with your car?
If you expect to climb rocks or navigate through mud, opt for 4WD. AWD can handle gentler off-road conditions, but may not have adequate road clearance for sudden elevation changes even on grass. If you want a balanced vehicle that offers a smooth-ride and excellent fuel efficiency vehicle that can still handle the occasional snowstorm or weekend adventure—AWD is a likely compromise.
If your car is strictly for commuting and fuel economy is your paramount concern, go with FWD. FWD cars are usually lighter and achieve better MPG ratings than their heavier AWD and 4WD counterparts. FWD also works best for minivans as a front-loaded drivetrain means a more spacious interior.
As discussed earlier, RWD is usually reserved for sports cars liked the Mustang and offers a more exciting driving experience than any other drivetrain. Other vehicles that leverage RWD are the workhorses for carrying firewood or towing a trailer. RWD is standard on most pickup trucks and large SUVs like the Tahoe or 4 Runner and most also come available with 4WD when more traction is needed.