For all those that want to save a little money on gas, here's a simple thing you can do to increase your gas mileage without much effort: Go to you local auto parts store and buy yourself a K&N air filter. These filters are different than your typical air filter and allow a lot more air into your engine, increasing both horsepower and gas mileage. I drive an '03 Toyota Tacoma. Up until now, the best gas mileage I ever got was around 19 mpg, and that was 100% highway. Last week I went out and bought a K&N air filter. This morning I filled up for the first time since installing the new filter. By my calculations, I got 20.5 mpg. And that was driving apprximately 60% highway, 40% city. I won't know what my true highway gas mileage is until my next road trip, but I can guarantee that it'll be higher than 20.5 mpg. The initial investment was a bit more than a regular filter. I paid $60 for the filter and recharger kit, whereas a typical filter for my truck runs around $15-$18. This thing is, I will never buy another filter again. These filters are guaranteed for 1 million miles and all you have to do is clean them once every 30K miles or so. I only need to keep my truck for another 80K miles before I've saved money simply on filters, let alone gas. And I definitely plan on keeping this truck until it dies, which could be a couple hundred thousand miles from now (I currently have 53K on it). These filters won't double your gas mileage, but with prices the way they are now, every little bit helps.