Why Parking in the Shade Can Save Gas and Keep Your Car Cooler

Parking your car in the shade on a hot summer day can help you save gas by keeping the interior cooler and reducing how much air conditioning you need when you start driving again. It also makes getting into your car more comfortable, especially when the seats, steering wheel, and dashboard would otherwise be sitting in direct sunlight.

You don’t need a garage or covered parking space to benefit. A shady spot under a tree or beside a building can make a difference, and a reflective windshield sunshade is a useful alternative when you have to park in the sun.

How Parking in the Shade Helps Save Gas

When your vehicle sits in direct sunlight, heat builds up inside the cabin. Sunlight passes through the windows and warms the dashboard, seats, and other interior surfaces, which then release heat into the surrounding air.

By the time you return, the cabin can be considerably hotter than the outside temperature. Your air conditioner has to work harder to remove that accumulated heat and bring the interior back to a comfortable temperature.

Running the air conditioner uses energy. In a conventional gasoline-powered vehicle, that generally means additional fuel consumption. According to the U.S. Department of Energy’s summer fuel-saving advice, parking in shaded or covered areas and using a sunshade can help prevent excessive cabin heat.

The actual fuel savings depend on the weather, how long the vehicle is parked, the air-conditioning system, and how you drive afterward. Parking in the shade won’t dramatically change your gas mileage on its own, but it’s a simple habit that can reduce the amount of cooling needed at the beginning of a trip.

Does Gas Evaporate From Your Tank When Your Car Is Parked in the Sun?

Gasoline is volatile, meaning it produces vapors that increase as temperatures rise. However, that doesn’t mean a modern car with a properly functioning fuel system simply loses a significant amount of gasoline every time it’s parked on a hot day.

Modern gasoline-powered vehicles are equipped with evaporative emissions control systems. These typically capture gasoline vapors in a charcoal canister and later route them into the engine, where they can be burned instead of escaping into the atmosphere.

The U.S. Environmental Protection Agency’s technical explanation of vehicle evaporative emissions describes how fuel temperature, vehicle age, fuel-system design, and vapor-control components affect emissions.

Some vapor emissions can still occur, particularly in older vehicles or those with defective or poorly maintained fuel systems. But avoiding direct sunlight isn’t a reliable way to produce measurable fuel savings through reduced evaporation from a properly functioning modern vehicle.

If you regularly smell gasoline around your parked car, don’t assume it’s normal evaporation caused by hot weather. A persistent fuel odor may indicate a leak or an emissions-control problem that should be inspected promptly.

What If You Can’t Find a Shady Parking Spot?

A reflective windshield sunshade is one of the easiest ways to reduce the amount of sunlight heating your parked car. It helps limit direct sunlight on the dashboard and other front interior surfaces, which can become especially hot when the windshield faces the sun.

Look for a sunshade that fits your windshield properly and is easy to fold or store. A well-fitting shade that you’ll actually use is more valuable than an expensive one that stays in the trunk.

Other practical ways to limit cabin heat include:

• Choose covered parking when convenient. A parking garage, carport, or shaded parking area can reduce direct sunlight on the vehicle.
• Consider where the sun will be later. A parking spot that’s shaded when you arrive may be in full sunlight when you return. If you’ll be parked for several hours, think about how the shade will move.
• Use additional window shades where appropriate. Shades designed for parked vehicles can help block sunlight through side or rear windows. Remove anything that could interfere with visibility before driving.
• Keep heat-sensitive belongings out of direct sunlight. Electronics, certain medications, and other temperature-sensitive items can be damaged by excessive heat. Some items shouldn’t be left in a hot vehicle at all, even in the shade.

You don’t need to drive around a parking lot repeatedly looking for the perfect shaded spot. If finding shade requires extra driving or a significant detour, the additional fuel used could outweigh the small savings from reduced air-conditioning demand.

How to Cool Down Your Car Without Wasting Gas

Even with careful parking, your vehicle may be uncomfortably hot when you return. Fortunately, you can cool it down more efficiently without immediately turning the air conditioner to its coldest setting.

First, open the doors or windows briefly to let some of the trapped hot air escape. Once you’re ready to drive, opening the windows for the first part of your trip can help remove excess cabin heat before you rely heavily on the air conditioner.

When the air inside has cooled, close the windows and use the air conditioner’s recirculation setting if appropriate. Recirculation allows the system to cool air that’s already inside the vehicle rather than continually drawing in hotter outside air.

Natural Resources Canada recommends parking in the shade, using window shades, briefly releasing hot cabin air, and using the recirculation setting to reduce air-conditioning energy demand.

Keep the temperature at a comfortable setting rather than making the cabin unnecessarily cold. There’s no need to sacrifice comfort or safe visibility to save a small amount of fuel, particularly during extreme heat.

Is It Worth Parking Farther Away to Get Some Shade?

Sometimes a shaded parking spot is farther from the store or building you’re visiting. Whether it’s worth choosing depends on the distance, the weather, and your circumstances.

If you can park in the shade a short walk away, you may return to a noticeably more comfortable vehicle. But if you’re carrying heavy groceries, traveling with someone who has limited mobility, or dealing with dangerous outdoor temperatures, a closer parking spot may be the better choice.

The same applies to paid parking. Paying a substantial premium for a covered space probably won’t make financial sense based on gasoline savings alone. The additional comfort and protection from direct sunlight may still make it worthwhile to you.

Remember That a Shaded Car Can Still Become Dangerously Hot

Parking in the shade helps limit heat buildup, but it doesn’t make a parked vehicle safe for children or pets.

The Centers for Disease Control and Prevention warns that parked cars can reach dangerous temperatures quickly, even when the weather doesn’t seem especially hot. Cracking the windows isn’t enough to prevent this.

Never leave a child or pet unattended in a parked vehicle, even for a few minutes or when the car is in the shade. Always check the back seat before leaving your vehicle.

For everyday driving, choosing shade when it’s convenient and using a windshield sunshade when it isn’t are inexpensive ways to make summer trips more comfortable. Any gasoline savings will generally come from reducing the need for air conditioning, rather than preventing substantial amounts of fuel from evaporating out of your gas tank.