How to get the best gas mileage for road trips: Calculators, tips, prices and more

As the busy travel season approaches, many families are planning their vacations and figuring out how they're going to get there.

That can mean a long road trip to see the grandparents or to the coast to get some sand between your toes. It's worth asking a few questions. Is your car ready for the journey? How do you maximize your fuel economy? How can you be mindful of fuel efficiency while you're planning the trip?

Patrick De Haan, head of petroleum analysis for GasBuddy, has pointers to follow for maximizing your gas mileage and possibly saving you money.

Warning to all lead foots: Your car will be more efficient at 55 mph than 70 mph. A speed of 55 to 60 mph on the highways is considered the best fuel economy for most passenger cars and trucks.

"On the highway, while you're going faster and consuming more fuel in the process, you may be more efficient than if you go 55 on a country road and you're stuck behind a lot of traffic that's slow-moving," said De Haan. "There can be trade-offs, but keep in mind, many times, your vehicle is going to be more fuel efficient at 55 miles an hour than it would be at 70 miles an hour."

"If you're above the speed limit, your car is really fighting a lot of that wind speed and friction," De Haan said.

De Haan said putting your car on cruise control on the highway can be one of the most effective ways to maximize gas mileage. Don't regulate your speed yourself and fall into the speed up-slow down cycle that many drivers take on.

"If you're not in a rush, setting your cruise control for the speed limit or slightly below really can reap dividends and cause your car to be much more fuel-efficient," said De Haan. "Using cruise control is probably one of the best things that people can do, especially for longer road trips."

Use your accelerator judiciously. The constant stopping and starting is one way to eat up a lot of fuel. The more braking and acceleration you do up hills or in heavy traffic, the less efficient your driving is.

We all dread seeing our check engine light or a tire pressure light.

Under-inflated tires can lower gas mileage and the check engine light can mean your vehicle isn't operating efficiently. Also, replacing a clogged air filter, while having little impact on fuel economy, can improve acceleration.

"Tire pressure is critical to your fuel efficiency," De Haan said. "Many times when those lights are illuminated, it will rob you of fuel efficiency."

If one of the dashboard lights comes on, swing by a mechanic before setting off on that trip. It could save you money and time down the road.

De Haan says to generally avoid adding things to the roof or back of your car, such as rooftop carriers. They can reduce your fuel efficiency by anywhere from 25 to 35 percent. The same reasoning applies for vehicles towing bikes or trailers. Aerodynamics are important on long road trips, especially when you're going highway speeds.

"They're generally not designed for your specific vehicle," De Haan said of carriers. "There's a lot of aerodynamic inefficiencies. It's basically like putting a mattress on top of your car, and it's really going to impact your fuel efficiency, especially those higher-profile rooftop carriers, the ones that look like it's a big pillow stuffed on top of your vehicle."

Depending on where you're going, you may have to pay more to fill up your tank. Gas prices generally vary depending on what part of the country you're in.

Fuel Tracker: Find lowest gas prices

"I think about things like gasoline prices in that state," De Haan said. "You know, if you're going from say, Charlotte to the west coast, you have a few different options for getting there. A lot of the time, if you take a more northerly route, you might end up paying a little bit more at the pump than if you go through areas like Texas and Louisiana and New Mexico."