But here's a new one: Drive like there's a glass of water on the dash. And to improve mpg but avoid the costly electrical damage or broken glass, Toyota in Sweden has produced a handy glass-of-water simulator app for the iPhone—which, it says, could reduce your consumption by ten percent.
You simply place your iPhone on the dash, in the cupholder, or on the passenger seat. The simple, elegant iPhone app shows drops splashing over the rim of the glass when you accelerate or brake too quickly; the droplets then "evaporate" within a few seconds to give you a chance to improve. However, since you should keep your eyes on the road, you can register for the app and login to the site afterward for an analysis of your driving.
"By planning your driving and driving calmer, you use less fuel and emit less CO2," says the info section for the app. "That's the simple key to ecodriving."