It's easy to forget how much of a difference speed can make when you're on the highway being overtaken by everybody doing 30 over the limit. Everytime I drive through a national park and the speeds are 70km/h to 90km/h max while the highway around can be 100km/h to 110km/h I'm reminded how good my Jeep can be on gas when you set the cruise at 70km/h and go for a few hours.

Using cruise helps a ton as well. Many people are pedal pumpers and maintain speed by continuously speeding up and coasting...very hard on gas.