I’ve been trying to think of ways to save on gas lately, and did some research. Lately there have been news articles about how some hybrid owners complain they’re not getting anywhere near the MPG ratings shown. But, these same drivers are trying to drive their new Prius like it’s a racecar. Driving habits have a huge impact on fuel consumption. Accelerating more slowly and not driving over 100kph/60mph can save up to 33% more fuel: Driving More Efficiently
Also, I stumbled onto this page that’s especially relevant up here in Canada: Idling: Myths Versus Reality. Apparently it’s somewhat harmful to idle cars for long periods and it becomes more energy efficient to shutoff and restart a car if it’d be idling for more than 10s. There’s lots of other interesting pages on those links above too.