One way to know if your car is in need of servicing is to simply do a gas audit. Next time you fill up on gas, take a note of your mileage. The next time you fill up, note the new mileage. The third time you fill up, compare the mileage used from the first and second fill-ups. If there is a decent size disparity between the two, there is a chance your car needs servicing. You can also check your car's owner manual to see what it states should be your vehicle's average miles per gallon. Anything that is substantially off is an indicator that something needs to be tuned up.

Is it more fuel-efficient to drive with your car windows down or with them up and the air conditioner on? Turns out, if you're on the highway going more than 55 mph, driving with your windows up is a much more fuel-efficient way to go. At high speeds, open windows create drag, which can reduce your car's efficiency as much as 20 percent. But at low speeds, when you're driving around town on surface roads, it's better to crack a window and leave the air conditioner off. There is less drag, and your car is producing less energy to operate, so feeling the cool breeze through the window is the greenest way to go then.

If you have a backyard pool, one easy habit to get into is to make sure it is covered whenever it's not in use. In just one week, a pool can lose about an inch of water if left uncovered. By simply covering it, you can help save as much as 95 percent of that evaporation. Covers also help conserve heat, which is another cost of owning a backyard pool; help keep the pool cleaner, since leaves and other debris are kept out; and it's safer.