How can I increase my Vauxhall Astra's fuel efficiency?

I have a Vauxhall Astra and I've noticed that it's not getting as good of gas mileage as it used to. What steps can I take to improve its fuel efficiency?

Firstly, make sure your tires are properly inflated. Underinflated tires can decrease your fuel efficiency. Additionally, try to avoid sudden accelerations and heavy braking. This can also contribute to lower fuel efficiency.

Another thing you can do is regularly change your air filter. A dirty air filter can decrease your car's overall performance, including its fuel efficiency. It's recommended to change your air filter every 12,000 miles.

Additionally, try to use cruise control on highways if your car has it. This can help maintain a consistent speed and lead to better fuel efficiency.

Also, make sure you are using the recommended grade of fuel for your Vauxhall Astra. Using a lower grade can negatively impact your car's performance and fuel efficiency.