Does Cruise Control Save Gas? When to Use It for Better Fuel Economy

Using cruise control can save gas when you’re driving on relatively flat highways with light, steady traffic. By maintaining a consistent speed, cruise control helps avoid the small, unnecessary accelerations that can increase fuel consumption. However, it isn’t always the most fuel-efficient choice, particularly on steep hills or in changing traffic conditions.

If you’re looking for an easy way to spend less on gas, using cruise control appropriately is a good place to start. The biggest benefits generally come from combining it with a reasonable driving speed and smooth acceleration.

How Does Cruise Control Save Gas?

Even when you’re trying to maintain a steady highway speed, it’s easy to gradually accelerate and then ease off the gas pedal without realizing it. These small changes may not seem significant, but repeatedly speeding up and slowing down can waste fuel.

Cruise control automatically adjusts the throttle or power output to maintain your selected speed. On a relatively flat road, this can help your vehicle travel more consistently than it might when you’re repeatedly adjusting the accelerator yourself.

The U.S. Department of Energy recommends using cruise control during highway driving, noting that maintaining a constant speed can reduce fuel consumption in most cases.

There’s an important distinction, though: cruise control doesn’t make your engine inherently more efficient. Its potential savings come primarily from helping you avoid unnecessary speed changes. A driver who already maintains a smooth, consistent speed may see little additional benefit.

When Does Cruise Control Work Best for Saving Fuel?

Cruise control is most useful when road and traffic conditions allow you to maintain a steady speed without frequent adjustments.

Good situations for using it include:

• Long stretches of relatively flat highway: Maintaining a consistent speed is easier when there are few hills, curves, or interruptions.
• Light, predictable traffic: When vehicles are moving steadily, cruise control can reduce unnecessary acceleration and deceleration.
• Long-distance road trips: Cruise control can help prevent your speed from gradually increasing during extended periods of highway driving.
• Familiar highway commutes: If part of your daily drive involves steady traffic and suitable road conditions, cruise control may help you maintain a more consistent pace.

You don’t need to use cruise control for every mile of a trip to benefit. Turning it on during suitable stretches and taking over when conditions change is often the more practical approach.

Can Cruise Control Use More Gas on Hills?

Yes. Cruise control can sometimes use more fuel than careful manual driving on hilly roads.

When your vehicle starts climbing a hill, cruise control tries to maintain the exact speed you’ve selected. Depending on the vehicle and grade, it may increase throttle significantly or cause the transmission to shift into a lower gear.

A driver managing the accelerator manually may be able to allow a modest reduction in speed while climbing, then regain speed gradually when the road levels out. This can avoid some of the extra fuel consumption associated with aggressively maintaining speed uphill.

For example, imagine you’re traveling at 65 mph and approaching a long incline. Cruise control may increase engine power to keep the vehicle at 65 mph throughout the climb. With manual control, you might safely allow your speed to decrease slightly, provided you remain within an appropriate speed range for the road and traffic.

That doesn’t mean manual driving is always more efficient on hills. Results depend on your vehicle’s transmission, engine, terrain, and cruise control system. Some newer vehicles have more sophisticated systems that manage changes in speed and power differently.

Never allow your speed to become unsafe or interfere with traffic simply to save fuel. On steep or winding roads, maintaining proper vehicle control matters more than minimizing gasoline consumption.

What Is the Most Fuel-Efficient Speed for Cruise Control?

Choosing the right speed is just as important as maintaining it consistently.

Driving faster increases aerodynamic resistance, which means your engine generally needs more energy to move the vehicle through the air. As a result, setting cruise control at a high speed can still use considerably more gasoline than driving somewhat slower.

According to a U.S. Department of Energy analysis of 74 vehicles, most achieved their best fuel economy at approximately 40 mph, with fuel economy typically declining sharply above 50 mph. The analysis also found that the average fuel economy decrease between 50 and 80 mph was 36%.

However, there isn’t one ideal cruising speed for every car. Vehicle weight, aerodynamics, engine design, transmission, and whether it’s a hybrid can all influence the most efficient speed.

For a more vehicle-specific comparison, consult your owner’s manual and the fuel economy information available through FuelEconomy.gov. Your owner’s manual may provide general economical-driving recommendations rather than an exact speed that delivers maximum miles per gallon.

The practical approach is to choose a legal, safe speed appropriate for traffic conditions rather than automatically setting cruise control at the highest permitted speed. Driving somewhat slower, when safe and reasonable, may save more fuel than cruise control alone.

How Much Gas Can Cruise Control Save?

There isn’t a reliable universal percentage that applies to every vehicle and driver. Your savings depend on how smoothly you normally drive, the speed you select, the terrain, traffic conditions, and the type of cruise control your vehicle uses.

If you frequently speed up and slow down on the highway, maintaining a steadier speed may make a noticeable difference. If you already drive smoothly, the improvement could be small.

Here’s a hypothetical example of how a modest fuel economy improvement might affect your spending.

Suppose you drive 1,000 highway miles and your vehicle normally averages 28 mpg. At an assumed gasoline price of $3.50 per gallon:

• At 28 mpg: You would use approximately 35.7 gallons, costing $125.
• At 30 mpg: You would use approximately 33.3 gallons, costing $116.67.
• Difference: You would save approximately $8.33 over those 1,000 miles.

These are hypothetical fuel economy and gasoline price figures used to demonstrate the calculation, not a prediction of what cruise control will save you. The actual change in fuel economy could be smaller, larger, or nonexistent.

If your vehicle has a trip computer that displays average fuel economy, you can compare similar journeys over time. Try to keep the route, speed, traffic, and weather conditions as comparable as possible. Even then, a dashboard comparison is only an estimate because many factors affect fuel consumption.

When Should You Avoid Using Cruise Control?

Saving gas should never take priority over safe driving. Cruise control is designed for suitable driving conditions, not every road or situation.

Avoid using conventional cruise control in the following circumstances:

• Rain, snow, or icy conditions: Reduced traction increases the importance of managing your speed directly. Follow your vehicle manufacturer’s instructions regarding cruise control on slippery roads.
• Heavy or unpredictable traffic: Frequent braking, merging, and speed changes make conventional cruise control impractical.
• Sharp curves or winding roads: You may need to adjust your speed frequently to negotiate turns safely.
• Steep or challenging hills: Manual speed control may provide better responsiveness and, in some circumstances, better fuel economy.
• Road construction or changing speed limits: Be ready to adjust your speed immediately when conditions require it.

Adaptive cruise control is different from conventional cruise control because it can adjust your speed in response to vehicles ahead. However, adaptive systems have operating limitations and do not replace an attentive driver. Consult your owner’s manual to understand when your particular system should and shouldn’t be used.

Regardless of the technology, keep your attention on the road and remain prepared to brake or take control immediately.

Other Ways to Save Gas on the Highway

Cruise control works best as part of an overall fuel-efficient driving approach. You can often make a bigger difference by paying attention to several everyday habits.

• Avoid unnecessary speeding. Higher highway speeds generally increase fuel consumption because of greater aerodynamic resistance.
• Accelerate smoothly. Sudden bursts of acceleration can use more fuel than gradually reaching your desired speed.
• Maintain a safe following distance. Leaving adequate space gives you more time to respond smoothly instead of repeatedly braking and accelerating.
• Keep your tires properly inflated. Follow the pressure listed on the vehicle’s tire information placard or in the owner’s manual, not the maximum pressure printed on the tire sidewall.
• Remove unnecessary cargo. Extra weight and external cargo carriers can reduce fuel efficiency, particularly at highway speeds.
• Keep up with vehicle maintenance. Address mechanical problems and follow the manufacturer’s maintenance schedule.

The Department of Energy’s efficient-driving guidance emphasizes driving behavior, vehicle maintenance, and sensible speed choices as ways to reduce fuel consumption.

Is Using Cruise Control Worth It?

For most drivers, cruise control is worth using on suitable highway stretches. It’s convenient, helps maintain a steady speed, and can reduce the small accelerations that add to your gasoline bill.

Just remember that cruise control isn’t automatically the most efficient option in every situation. On hills, in heavy traffic, or when road conditions are poor, taking manual control may be safer and more practical.

If your goal is to spend less on gas, the simplest habit is to use cruise control when conditions are appropriate, choose a sensible highway speed, and avoid unnecessary acceleration. Together, those habits can help you get more miles from each tank without sacrificing safety.