Your Car May Be Burning More Gas This Fall — Here’s the Surprising Reason Why

Many drivers notice that their car seems to burn through fuel faster in the fall than it did during the summer. Several physical factors are responsible, and they begin working together as temperatures drop. Here’s a closer look at why fuel economy can decline during the fall months.

What Changes When Temperatures Drop

Colder weather changes the conditions under which a vehicle operates and can force the powertrain to work harder.

One of the biggest factors is the time it takes the engine to reach its normal operating temperature. Until it warms up, the engine computer typically delivers a richer fuel mixture to the cylinders, while cold engine oil becomes thicker and creates additional internal friction.

In summer, this warm-up period may last only a few minutes. In the fall, however, it can take up a much larger portion of a short trip. That’s one reason experts recommend combining several short errands into a single trip. Once an engine is fully warmed up, it generally operates more efficiently and uses less gasoline.

Another factor is the air itself. Cold air is considerably denser than warm air.

As a vehicle moves at highway speeds, denser air increases aerodynamic drag. The engine therefore has to produce more power to push the vehicle through the air, which can result in additional fuel consumption.

Why Tire Pressure Drops in the Fall

Fuel economy can also suffer because tire pressure naturally decreases as outdoor temperatures fall.

The air inside the tires contracts in colder weather. Underinflated tires create greater rolling resistance, forcing the engine to work harder to accelerate and maintain speed. That extra resistance can translate directly into lower fuel economy.

To keep fuel consumption under control, drivers should check their tire pressure regularly with a gauge and inflate the tires to the pressure recommended by the vehicle manufacturer.