In FUEL, players are given the freedom to roam. The game practically defines open-world by allowing players to take any shortcut they can find to get ahead. This includes blind jumps off cliffs and driving through burning forests. However, taking shortcuts are also likely to produce disastrous results, since a single ill-placed tree or rock can stop your vehicle cold. Similarly, vehicles are designed to perform best on specific terrain, and it's not uncommon for races to switch between on and off-road driving, so a patch of dirt or overly steep hill can cause players to spin their wheels in place and potentially cost them the race. At times, the game is inconsistent with its obstacles. Some bushes appear to be strictly cosmetic and can be driven through safely, while others that look identical will bring the vehicle to a complete halt.

There's a great variety of racing modes, including one where players need to outpace a helicopter, but things don't really get interesting until the player unlocks Drownington Cove, the destroyed remains of San Francisco. That's where players start to see big weather effects that go beyond the occasional rainstorm. There's a mode where tornados collapse structures and throw debris into the middle of the road. However, even though these racing modes help to liven things up a bit when combined with the diverse terrain and wide-open areas to explore, FUEL mostly ends up being a fairly mundane racing game.

At the start, players are dropped in the middle of nowhere and are more-or-less left to fend for themselves. Players advance in their career by winning the star races and earn extra fuel (the game's currency) by beating challenges spread out over the zone. Players buy better cars and unlocks new areas, where they can go to do more of the same. Drivers also have the option to freely drive across zone looking for new challenges, patterns to add-on to vehicles, or just to take in the gorgeous scenery. To this end, some places have trucks that will reveal all the challenges, patterns or designated vista locations within the zone. All players need to do is track them down and bump into them. Additionally, players can find elite class vehicles out roaming the zone. The downside is, players need to cover a lot of ground to reach these key points.

Despite being deemed in inhospitable, most of the areas are still beautiful, especially when the sun rises and sets on the horizon. Much of the time, the only thing that makes it seem inhospitable is all the junk that's left lying in the middle of the road. Yet, even with the freedom to drive down steep mountain sides or jumping off cliffs, the free driving mode gets old pretty fast. If you've ever been on a long trip where there's nothing but road and trees ahead of you for miles, then you already have an idea of what free driving across the Northwest is like. Once you've seen on debris-ridden highway, you've pretty much seen them all, and the same goes for the forests and winding mountain roads. There's nothing to break up the monotony and sense of lonesomeness except for the occasional truck that happens to pass by or get in your way. A 3D GPS puts arrows and a compass in the sky to help players navigate the complex network of asphalt and dirt roads, but the system has its quirks. The GPS doesn't take into account the type of vehicle the player is driving and will direct players to drive straight through lakes. Also, the constant terrain changes make it necessary to constantly switch out vehicles until players can find one that has the best balance of speed and versatility. This is all when the GPS is working as it should and not leading the player in confusing directions, as it is occasionally prone to do. There's no way to set the GPS with preferences, like sticking to paved roads whenever possible and avoid going through bodies of water. So even with a navigation system, players are often left to figure things out for themselves.