What's the best way to maintain my Toyota Highlander's fuel efficiency?

I recently bought a Toyota Highlander and I want to make sure I am getting the most out of my fuel. I've heard conflicting advice about how to maintain fuel efficiency, such as turning off the AC or using a higher quality fuel. What methods have you found to be most effective in preserving the Highlander's fuel efficiency?

I have found that using a higher quality fuel (such as premium or diesel) and keeping up with regular maintenance (oil changes, tire rotations, etc.) have helped me maintain fuel efficiency in my Highlander.

Turning off the AC can make a small difference in fuel efficiency, but in the long run it's important to prioritize regular tune-ups and maintenance. Keeping the tires properly inflated can also help improve fuel efficiency.

I have found that using a fuel additive specifically designed for fuel efficiency can help improve my Highlander's gas mileage. It's also important to avoid idling for long periods of time and to not overload the vehicle with excess weight.