Why is my Vauxhall Grandland's gas mileage decreasing?

I've noticed that the gas mileage on my Vauxhall Grandland has been decreasing over the past few months. I used to average around 30 miles per gallon, but now I'm only getting around 20 miles per gallon. What could be causing this and what can I do to improve it?

There are a few possible reasons for a decrease in gas mileage. It could be due to a dirty air filter, worn spark plugs, or even low tire pressure. To improve your gas mileage, try getting regular maintenance check-ups and keeping your tires properly inflated. Also, consider using a fuel injector cleaner every now and then to keep the engine clean.

Another factor that could be affecting your gas mileage is your driving habits. Are you constantly accelerating and braking aggressively? This can significantly decrease your gas mileage. Try to drive more smoothly and avoid sudden stops and starts.

Have you recently changed your driving route? City driving generally requires more gas compared to highway driving. If you've been doing a lot of stop-and-go driving, this could explain the decrease in gas mileage.