This Cruise Control Mistake Won't Save You Money On Gas

If you're an aggressive-style driver who frequently goes on road trips, cruise control could serve as a reliable way to help increase your miles-per-gallon (MPG), cutting down gas consumption and consequently saving you money. According to the U.S. Department of Energy, every 5 mph above 50 mph adds 22 cents per gallon of gas, assuming fuel costs $3.13 per gallon. Meanwhile, an Edmunds test over a 55-mile road proved that you can also save almost 15% more gas using cruise control. So, for drivers who are prone to going too fast, cruise control will conserve fuel and avert a possible speeding ticket (which usually ends up costing much more than you realize). It's not as effective as some other methods to save you money when buying gas, but it could work — as long as you're using it the right way.

Without cruise control, it's difficult to keep consistent speeds, and slowing down and speeding up is a driving mistake that costs you at the pump. A Natural Resources Canada study showed that you can reduce gas consumption by 20% by cruising steadily at around 50 mph instead of frequently revving up and down. However, you won't be saving any gas if you make the mistake of using cruise control to keep a steady speed in hilly terrain and on city streets, or on roadways that are icy or wet.

The best scenario for pocket-friendly cruise control is a road trip on a long, flat highway. Since cruise control is essentially a computer feature in your car that maintains a steady speed, a smooth highway with few stops, hills, or other obstacles is exactly what it's designed for. 

Cruise control can't tell terrain the way a driver does, which means it often pushes throttle more to keep you at the set speed, even when it's unnecessary. Whereas you would slow down naturally on the way up and regain speed on the way down, cruise control's goal would be to keep you at your set speed no matter where you are. This leads to higher fuel consumption and more engine strain in hilly areas.

City driving is another scenario in which cruise control doesn't work. Apart from the fact that cruise control isn't meant to be used in a city full of traffic, the adaptive cruise control that was designed for more congested areas sometimes doesn't offer the same efficiency advantage either. Adaptive cruise control is programmed to keep a safe buffer between you and the car ahead, which means it often brakes earlier and then accelerates faster than most skilled drivers. This robotic stop-and-go pattern wastes gas and burns through brake pads faster.

The third scenario is wet or icy roads. In low-traction conditions, cruise control can actually make your car less stable, since it keeps applying throttle even when the tires start to slip. Instead of helping, it increases the risk of skidding — which could cost you expensive repairs or even pose serious safety risks.

When the road starts climbing, resist the urge to floor the gas pedal. It's best to keep your foot off the gas pedal at times, allowing your car to climb at a slower pace. Doing so reduces strain on the powertrain and prevents unnecessary fuel burn. As gravity gives you an advantage on the way back down, ease off the accelerator and let momentum carry you.

Downshifting smartly can help, too. Many experienced drivers suggest shifting into a lower gear on steep declines rather than riding the brakes. This technique saves your brakes and gives you steadier control going downhill. With brake pads costing $100 to $300 per axle, this is certainly the cheaper way to descend hills. On the climb, using a higher gear too long also forces the engine to work harder, so timely downshifts help you maintain torque efficiently without spiking fuel consumption.

Finally, anticipate the terrain. A good driver would "look through the hills," scanning ahead so they can gently build speed before the incline, then release pressure as the crest the top. This rhythm allows you to use stored kinetic energy more efficiently, similar to a rolling wave, rather than the fuel-hungry surging and braking in bursts.