• A record number of Americans are expected to take a road trip during the July Fourth holiday week, according to AAA.
• In certain cases, renting a car may be more financially savvy than using your own vehicle for a road trip.
• There are many things to consider: vehicle health, rental and insurance rates, fuel efficiency, depreciation and lease contract details.

Summer is the season of road trips.

A record 70.9 million Americans are expected to travel by car during the July Fourth holiday week alone, according to AAA.

For some car owners, it might be more financially savvy to rent a vehicle for a road trip than use their own, experts said.

"It's going to be pretty dependent on a variety of factors," said Greg Brannon, AAA's director of automotive engineering research.

Those factors include your current vehicle's gas mileage, the distance you'll be driving, how long you'll be gone, whether you lease or own and how big your vehicle is, among other things, according to Toyota.

Here are some key considerations.

The car's specs

Vehicle capacity is a "no-brainer" when it comes to choosing whether to rent or not, said Brian Moody, executive editor of Autotrader, a car shopping site.

It's easiest to say, "I have a five-passenger car and I have eight going on the trip," Moody said.

Drivers may also need to compare specifications, such as the necessity of a two-wheel-drive versus a four-wheel-drive car, as well as storage space for luggage and gear.

Operating costs

This is where the math gets a bit trickier. There are many financial costs, some obvious and others less so.

Drivers would need to compare total rental costs — the daily rental rate and potential add-ons like insurance — versus those of operating their own car.

"Most people will be shocked at what it actually costs to own and operate their car," Brannon said.

Fueling costs, such as gasoline or electric charging, are a financial consideration for both renters and car owners.

It may be possible to rent a more fuel-efficient vehicle and save money. For instance, renting a car that gets 40 miles per gallon versus a currently owned one that gets 20 mpg would, all else equal, cut fuel costs in half.

"If you have an old car that's fuel inefficient, it might make sense to rent something," Moody said.

Rental costs

The average rental cost $42 a day in the second quarter of 2024, with most travelers looking for four-day rentals, according to travel site Hopper.

The daily rate can be higher or lower based on factors like rental company, car type, and pickup and drop-off location.

The cost of rental car insurance might add $30 to $61 to the daily rate, depending on insurance type, according to Allianz Travel, citing MarketWatch data.

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Renters who want car insurance may not need to buy additional coverage through the rental company.

Car owners may already get full coverage on a rental via their own car insurance policies, or may have some coverage through credit-card benefits, Brannon said.

"Call your insurance agent and double-check your coverage," he said. "You can save yourself a bunch of money by not double-insuring the vehicle if you don't need to."

Depreciation and mileage caps on leases

Additionally, car owners who lease a vehicle should weigh factors like mileage caps before taking a long road trip. For example, the typical lease imposes financial penalties on drivers who put more than 12,000 miles a year on their vehicle, according to Kelley Blue Book.

The cost for exceeding that cap is usually about 20 to 30 cents per mile, KBB said. (At 30 cents, a driver would pay $300 for every 1,000 miles over the mileage limit.)

There are also depreciation costs to consider.

Depreciation causes a car to lose value over time. Cars famously lose about 10% to 15% of their value once they drive it off the lot, Brannon said.

Depreciation is "the biggest expense of owning a vehicle," Brannon said. And that's why it matters for road trips, he says.

"The more miles you put on a vehicle the more it depreciates," Brannon said.

Every mile puts wear and tear on the engine, tires and other moving parts, according to Allianz.

Depreciation affects all cars differently. The average car depreciates at about 20 cents a mile, according to Toyota.

For shorter road trips — say, 1,000 to 1,500 miles in a given year — depreciation might not be a big deal relative to rental prices, said Autotrader's Moody.

Depreciation generally only matters for people who plan to sell or trade in their vehicle in the future.

State of the vehicle

Unforeseen repairs can be costly: The average repair order on the road is "well in excess of $500," excluding towing costs, Brannon said, citing AAA data.

The odds of a breakdown are lower with rental cars, which are generally newer models, Moody said. The average used car on the road is about 12 years old, he explained.

While a mechanical issue would be inconvenient for anyone taking a road trip, renters wouldn't be financially liable (assuming they're not at fault), Moody said.

Brannon points out some questions drivers should ask: Have I done a good job maintaining my car? Is it up for long days on the road? Are the tires in good shape? Is it mechanically sound? How old is it? What safety technologies does the vehicle have?