Using the car's energy-saving mode when available is an effective way to reduce fuel consumption and save money on gas. Energy-saving mode is a feature available in some cars that optimizes the car's performance to reduce fuel consumption and emissions.

Energy-saving mode works by adjusting the car's engine and other components to operate at their most efficient levels. This includes reducing the car's power output, adjusting the transmission's shift points, and optimizing the use of accessories like air conditioning and heating.

By using energy-saving mode, you can reduce your car's fuel consumption by up to 5-10%. This can translate to significant savings over time, especially if you drive frequently or have a long daily commute.

To use energy-saving mode, check your car's owner's manual or consult with your car's manufacturer or dealer. Some cars have an energy-saving mode button that you can press to activate the feature, while others may have it automatically activated when certain conditions are met, such as driving at a steady speed on the highway.