Are AWD cars more expensive to maintain than FWD?

The short answer is yes, an all-wheel drive vehicle is more expensive to maintain for one simple reason: an AWD vehicle has more components. The more important question is how significant is the difference?

To compare apples to apples, let's look at two similar vehicles, one with FWD and the other with AWD. We picked a front-wheel drive Nissan Altima sedan and an all-wheel drive Nissan Rogue compact SUV, both of the same model year, equipped with the same 4-cylinder engine.
Nissan Rogue and Nissan Altima2018 Nissan Altima and Nissan Rogue. Photo courtesy of Nissan North America.
What is the difference in fuel, maintenance and repair costs?

According to EPA estimates, the AWD Rogue will cost around $150 more a year in fuel, if driving 15,000 miles a year. We suspect in real life, this number will be a bit higher, but it's not a huge difference.

What about regular maintenance? The price for oil changes is the same. A set of tires for the Rogue (they are larger) costs about $200 more; tires are usually replaced within three years assuming you're driving an average of 15,000 miles per year. The price for an all-around brake job is also almost the same. The cost for the wheel alignment, air filter, drive belt or spark plug replacement is roughly the same for either vehicle.
The Rogue has a simple all-wheel drive system based on front-wheel drive, similar to many other compact SUVs. It's a light-weight setup that is effective on slippery roads, but is not intended for heavy-duty off-roading. The Rogue AWD system has a small power transfer unit (transfer case) and a rear differential, see the diagram.
Diagram of FWD and AWD mechanical components FWD and AWD mechanical components: 1. 2. Front CV axles. 3. Transfer case (unit). 4. Drive (propeller) shaft. 5. Rear differential. 6. 7. Rear CV axles.
The Rogue's maintenance schedule only mentions inspecting the fluid in both components. The reality is that both components will probably require fluid change within four years under average driving conditions. Replacing the fluid (gear oil) in both components will cost $200-$300. The Rogue AWD system also has a driveshaft (prop shaft) that transfers the power to the rear differential and two more CV axles at the back, but they don't need any maintenance. Read more: What is the difference between FWD and AWD? Pros and Cons.

All in all, the AWD Rogue will cost at least $600 more in fuel, plus another $400-$500 in maintenance over the first four years. Considering the benefits of the AWD, it's reasonable. However, in an all-wheel drive vehicle the cost of repairs will increase significantly at higher mileage if some of the AWD components fail. The proven reality of the automotive world is the more complicated the car is, the more chances that something will go wrong. In addition, some of the common repairs, such as rear wheel bearing replacement, will also cost more in an AWD vehicle due to extra labor.