Does AWD Hurt Fuel Efficiency? How The Feature Impacts Your MPG

Cars come in all sorts of varying configurations -– unique trim levels offer varying equipment, different levels of luxury features, paint colors, wheels, and often the choice between two and all-wheel drive. Compared with their two-wheel drive counterparts, all-wheel drive cars have the benefit of increased all-weather capability, especially if you live in an area with lots of rain or snow. There is a drawback worth noting, though: decreased fuel economy. 

Yes, all-wheel drive can hurt your fuel efficiency. When it comes to fuel economy, weight is the enemy. All-wheel drive vehicles are heavier than their front-wheel drive or rear-wheel drive counterparts. The extra weight comes from the driveshaft or axles required to move all four wheels instead of just two. More components mean more weight, which means more power is required to move the vehicle around at the same speed. Creating that power requires more fuel, so fuel consumption is up, and MPGs go down. Also, sending power to all four wheels requires more energy (fuel) than sending that power to just two wheels. While there are differences between four-wheel drive and all-wheel drive, the same is true of four-wheel drive vehicles as well -– they use more energy and weigh more than their two-wheel drive counterparts.

Using the hybrid Toyota Prius as an example, let's look at fuel economy estimates between versions of a car. According to the EPA, the front-wheel drive Prius is capable of returning 57 miles per gallon combined (57 city/56 highway). The EPA's estimates change with the AWD model, dropping down to 54 mpg combined (53 city/54 highway). The EPA also provides estimates for the annual cost of fuel, with the standard Prius checking in at $800 and the AWD model costing $850. The annual fuel estimates are based on 15,000 miles at current fuel prices, with the split set up as 45% highway driving and 55% city driving, so the cost could change depending on your commute.

This price difference is a little bit more pronounced on big, four-wheel drive vehicles like the Toyota Tundra. There's an impressive and efficient Tundra hybrid available, but on the standard Tundra with the 3.4-liter V6 powertrain, the EPA estimates 22 mpg combined (20 city/24 highway), with an annual fuel cost of $2,100. (Yikes – that Prius is looking pretty good.) Go with the four-wheel drive version of the same truck, and the EPA estimate drops to 20 mpg combined (19 city/22 highway), increasing the annual fuel cost to $2,300. The fuel-economy difference between the two Tundra configurations is smaller (just 2 mpg combined, compared to the Prius' 3 mpg difference), but since the starting point for annual cost of fuel is higher, the gap between the two models increases as a result.