The seemingly infinite freedom and convenience of owning a car can suddenly come crashing down around you when it's time to head to the gas station. Rising fuel prices appear to be an inevitability in today's world, which means drivers everywhere have a vested interest in doing whatever they can to get the most out of their gas mileage.

Fortunately, cars are being made that are more fuel-efficient than ever. If you're a used-car owner, however, it's much more helpful to devise ways to get the most out of your existing ride without having to shell out major bucks for a newer car. 

Here are a few tips for milking your mileage and saving some money at the pump.

Keep your car in good shape
This should go without saying, but it's an important gas mileage-related point so it bears repeating. Reason dictates that the better overall shape your car is in, the more efficient it's going to be when it comes to gas mileage. You may be aware of some basic maintenance functions like keeping your oil fresh, but there are other low-level maintenance tasks you can take care of right at home that will keep your gas mileage where you want it to be. Advance Auto Parts noted that poorly maintained spark plugs can reduce your fuel efficiency by up to 12 percent, while something as simple as a dirty air filter can leave your car 20 percent less fuel efficient.

Don't neglect your tires
Your tires are the unsung heroes of your car. You may be aware of the important safety role they play, but they are also significant in keeping your gas mileage in the black, too. The blog Get Rich Slowly noted that underinflated tires can reduce your fuel efficiency by up to 25 percent, while overinflated tires can similarly impact your fuel efficiency in a negative way.

Drive smart
You may be interested to know that when it comes to maximizing your fuel economy, the onus isn't entirely on your car. Your behavior and driving habits can have just as big an impact on how many miles per gallon you get. Anyone who's a veteran of city driving is no stranger to the familiar cadence of stop-and-go traffic, but did you know it's terrible for your fuel efficiency? Repeated accelerating and braking can drop your fuel efficiency, according to Popular Mechanics. For weekday commuters, this may mean getting creative with your work schedule so you can plan your commute around the rush hour period when this type of driving is more or less unavoidable.

Do double duty
Do you need to run to the post office over the weekend to drop off a package? What about heading downtown to catch the final day of a sale at your favorite clothing store? There are constantly little errands that we find ourselves running, but if you take a minute and do some planning, you can reap the benefits when it comes time to head back to the pump. Stop-and-go driving is terrible for your fuel economy, and that goes for taking short jaunts out to various destinations around town and back. Not only will this help you save money at the gas station by cutting down the overall distance you're driving and, by extension, the amount of fuel you're using, but you'll also likely find that it has a positive impact on your time management, as well.

Don't trust miracle products
These days it seems you can find a magic bullet for any occasion, and improving your gas mileage is no exception. But as the old saying goes, if it sounds too good to be true, it likely is. Unfortunately, this maxim applies to these miracle products claiming to boost your fuel efficiency. According to the U.S. Federal Trade Commission, there are currently no products on the market that have been approved to actually improve your car's fuel efficiency, which means any bottle, can or box you find on the shelf at your local auto supply store that claims to do so is lying. Even worse, some products can actually worsen your car's gas mileage, essentially meaning you're paying even more for less.

If you'd rather trade in your car for a more fuel-efficient model, head to New Jersey State Auto Auction. You'll find hundreds of Carfax-certified cars on the lot, and you're bound to drive away in the used car that's perfect for your needs.