Does opening the car hood help cool the engine or EV battery?

Most modern electric vehicles (EVs) feature high-capacity batteries installed beneath the floor, enclosed in a protective casing and equipped with dedicated cooling systems, either via liquid circulation or fans. According to Car and Driver, automakers have developed software-based battery health management systems that include both cooling and heating functions to improve efficiency in a wide range of temperatures.

Beneath the hood, critical components such as power converters, chargers, electronic control units, and high-voltage distribution modules generate heat during operation. These parts are equipped with their own cooling mechanisms, typically involving liquid circulation and fans.

Therefore, opening the hood during charging or driving does not assist in heat dissipation. In fact, this practice increases the risk of dust, rainwater, insects, or small animals entering the vehicle, potentially causing short circuits. If the hood is not securely closed before driving, it can open unexpectedly, obstruct visibility, and lead to accidents.

Gasoline cars with hoods open. Illustration by Pexels

Chase Auto advises EV owners to adopt the following habits to prevent overheating: park in a garage, covered lot, or shaded area; keep the EV clean and clutter-free to reduce unnecessary weight; and avoid driving or charging during the hottest parts of the day. A test by What Car? magazine found that driving in extreme heat can cause EVs to lose up to 44% of their claimed range, according to Wales Online.

For internal combustion engine vehicles, automotive accessory brand Accelera Radial warns that opening the hood does not effectively reduce engine temperature. In fact, this practice may cause additional problems.

The temperature inside a car engine does not vary significantly whether the vehicle has been running for one hour or two hours, even under heavy traffic conditions or on highways. This is due to the presence of fully integrated cooling components, including radiators, cooling fans, and other systems. As long as these systems are functioning properly, the engine temperature remains within optimal limits.

Regular maintenance at an authorized service center is crucial to ensuring the engine cooling system operates efficiently. Drivers should be vigilant if radiator fluid levels drop rapidly or if the temperature gauge indicates unusually high readings.