Planning Trips With Fuel Stops & Mileage

Nothing captures the mystique of travel quite like zooming down an open road with the wind in your hair. Of course, nothing captures the misery of a trip gone wrong like finding yourself marooned between towns, watching your gas gauge sputter to "E" as the sun goes down. Happily, a little careful planning, with an eye toward distances between communities, road conditions and where you can or can't get gas, is all you need to keep your road trip on track.

If you have a road trip in mind, you probably already have a starting point and an end destination picked out. The next step is choosing how to get there. For example, if you're driving from San Diego, California, to Portland, Oregon, you could just take the fastest route north on Interstate 5. But if you're doing a leisurely road trip, you're probably in it for the views, so you might want to consider taking the wild and beautiful Pacific Coast Highway – even though it more than doubles your driving time.

As a general rule, cars and trucks are more fuel efficient on the highway than in stop-and-go city traffic. To calculate your car's total range, multiply its average highway miles per gallon by its fuel capacity. For example, if your car averages 25 miles per gallon on the highway and has a 12-gallon fuel tank, its range is 25 x 12 = 300 miles.

Your actual mileage will vary, however, and if you spend enough time on the road you're guaranteed to run into traffic delays or detours. So multiply that total range by 0.75 to give yourself a quarter-tank reserve between fill-ups. In this case, 300 miles x 0.75 = 225 miles as an ideal distance between fill-ups.

Now that you know your vehicle's range, it's time to plan out where you'll gas up. You can count on finding 24-hour gas stations in major cities, but smaller towns might have gas stations that are only open for limited hours or, in truly remote rural areas, no gas stations at all. Your favorite mapping app, websites like GasBuddy.com and mobile apps like Gas Guru can all help you not only find gas stations but also estimate gas prices, either at a specific station or for your entire trip. When it comes to budgeting for gas, keep in mind that prices can vary wildly from town to town and state to state, and may change while you're on the road. Tools like AAA's gas price calculator are very useful for calculating your total gas budget. Once you have that estimate, add at least 10 percent as a buffer against changing gas prices, just in case.

Now that you know where you're going and where to fill up along the way, it's time to decide how to break up your days. This is a personal choice that depends on your physical endurance, tolerance for motion sickness or time spent in the car, and how much time you want to spend taking photos, hiking, visiting museums or otherwise exploring the places you pass through. For most people, six to eight hours of driving time – or between 300 and 500 miles per day – works out to a long but manageable day. Most people will also enjoy having a rest day every three or four days to recuperate from the physical demands of spending so much time in the car; try to plan these stops in communities or regions that you want to spend some time exploring.

Running out of gas isn't the only easily avoidable problem that you might encounter on the road. Before you go, make sure your tires are fully inflated, including the spare, and that you have all the necessary tools to fix a flat. That includes a jack, tire chocks, tire iron and, if your vehicle has locking lug nuts, the key to loosen them. Many travelers like to carry a small combination battery pack and air compressor that lets them jump-start their own car and refill flat tires. If you're not comfortable performing this sort of basic maintenance on the road, now's the time to invest in coverage for roadside assistance.

Next, make sure you have a car charger for your cell phone, plus water and snacks in case you break down or get stuck in traffic. And if you're traveling through very remote areas, it's best to carry extra layers of clothing and a sleeping bag or blanket too.

Last but not least, consider carrying a small gas can with an emergency reserve. If you've researched well and calculated for that quarter-tank reserve on your car's usual range, you probably won't need it. But just like the sleeping bag and other emergency supplies, it's the sort of thing you'll be very grateful to have in the rare occasion that disaster does strike – and even if you don't need it, you might be able to help someone else who's run out of gas.