ALTOONA, Pa. (WTAJ) — Like clockwork, gas prices will start to increase as companies switch to their summer blend, but what exactly is summer blend and why do we pay more for it?

Actually, you may be saving money as the summer blend, which many states have regulations for, is meant to be less volatile, preventing the summer heat from evaporating the gas in your vehicle — preventing possible engine damage.

The actual term is Reid Vapor Pressure (RVP). The lower the RVP, the lower the volatility. The blends actually vary from state to state and region to region due to state regulations that are in place, according to GasBuddy.

While the Environmental Protection Agency (EPA) requires the lower-volatility summer blend, gasoline’s RVP is limited so that fuel does not vaporize in a vehicle’s fuel system. If it does, the engine can stop running.

According to NACS, the summer blend fuel can add up to 15 cents per gallon, in addition to higher prices due to summer fuel demand, which can vary between 5-15 cents per gallon.

The price-increasing summer blend is in rotation from May 1 to Sept. 15, in accordance with EPA regulations.

In winter, gasoline blends have a higher RVP. They evaporate more easily but allow gasoline to ignite more easily to start your vehicle in cold temperatures. This makes the blend cheaper to produce, which is why we tend to see lower prices from late September through late April.