America might not have the most expensive gas prices in the world, but they aren't cheap. Because of this, you may be looking for ways to increase your car's fuel efficiency to save some cash at the pump and maybe protect a few polar bears in the process, but is the very drivetrain in your car actually hindering your progress?
If you're driving an all-wheel drive car, you may feel like the superior traction you get on loose surfaces and the go-anywhere mentality that comes with AWD is nothing but a good thing. Those pros of an AWD can come with some downsides, however, like the fact that an AWD setup can hit your car's fuel efficiency.
A variety of factors mean that, in many settings, an AWD car can be less efficient than its two-wheel drive counterparts, but just how much excess fuel are you really burning with your AWD drivetrain?
The reason your AWD car burns more than its front or rear-wheel drive rivals comes down to two major factors: the weight and complexity of AWD systems, as a Washington Subaru dealer explained in a recent blog post:
This is due primarily to the extra weight and mechanical resistance that AWD equipment adds to the frame of the car. Heavier vehicles naturally require more energy to accelerate and decelerate, and that affects the overall MPG you can expect from your vehicle. Vehicles with AWD tend to be larger-bodied cars in general, too, like SUVs and trucks, which also contributes to the average fuel economy.
The added weight of AWD means that your car's engine works harder to keep up with lighter, less complex 2WD models. This means that over the course of a drive, you'll probably burn more fuel in an AWD car than you would with front or rear-wheel drive.
It's tricky to put an exact figure on what AWD will actually do to your car's efficiency, as there aren't a ton of cars available as AWD and 2WD options. Estimates suggest that cars with AWD engaged lose one or two mpg compared to 2WD versions, according to research carried out by the Environmental Protection Agency.
The drop in efficiency is even greater if you have a four-wheel drive car, which is heavier and more complex. In 4WD cars, the drop in fuel economy can be as much as three mpg compared with 2WD models.
Of course, these negatives can be offset by the positives of an AWD vehicle. For example, you might find that the increased traction and performance you get on some surfaces with a 4WD or AWD model outweighs the hit on fuel efficiency, so the decision on which is better for you will all come down to weighing up the pros and cons.