Why does my Kia Sportage's fuel efficiency decrease after driving at high speeds?

I have noticed that after driving my Kia Sportage on the highway for an extended period of time, the fuel efficiency seems to decrease significantly. What could be causing this issue?

This issue could be caused by a number of factors. One possibility is that your tires may be under-inflated, which can cause increased resistance and decrease fuel efficiency. Make sure to regularly check your tire pressure and inflate them to the recommended level.

Another potential cause could be a dirty air filter. A clogged air filter can restrict air flow to the engine, leading to decreased fuel efficiency. Consider replacing your air filter if it has not been changed in a while.

Driving at high speeds can also cause your engine to work harder, using up more fuel. Try to maintain a steady speed and avoid unnecessary acceleration and braking.