How can I improve the gas mileage of my Vauxhall Astra?

I've noticed that my Vauxhall Astra's gas mileage has been decreasing lately. What are some tips or maintenance steps I can take to improve its fuel efficiency?

One way to improve gas mileage is to make sure your tires are properly inflated. Under-inflated tires can decrease fuel efficiency.

Have you been keeping up with regular oil changes and tune-ups? These can greatly impact your car's gas mileage.

Consider your driving habits as well. Avoid aggressive driving and try to maintain a constant speed on the highway for better fuel efficiency.