LOS ANGELES (KABC) -- Have you looked around the trunk of your car lately?
Turns out more than a third of 2015 model-year cars sold don't have a spare tire according to an AAA analysis. Instead, some car makers provide sealant kits and some others install so-called run-flat tires.
But be careful. Consumer Reports says while those specialty tires work even after a puncture, they do have some drawbacks.
Gloria Strunin recently leased a new car that has no spare tire. She drives long distances by herself to see her family and was alarmed to learn she'd have to depend solely on her run-flat tires in case of a puncture. She's worried about their run-flat 50-mile range.
"It was a big concern of mine and it still is to this day," Strunin said.
Consumer Reports tire expert Gene Petersen says run-flat tires have thicker sidewalls than traditional tires. Most manufacturers say they will support the car at speeds up to 50 miles an hour for a distance of at least 50 miles after most flats.
But he has a caution.
"They're not going to work for everything, so if you do have a ripped sidewall, if you do have a large hole in the tire, obviously you may not be able to drive on it," Petersen said.
Run-flat tires are also more expensive than regular tires. Depending on size some can cost as much as $300 each. There are also fewer models available, and they might have to be special-ordered.
Why are so many car makers ditching the spare for run-flat tires?
"Manufacturers are eliminating the spare to lighten up the load in the car to help improve fuel efficiency," Petersen said. "In the case of run-flat tires though it may also be because they don't have room in the car for a spare tire."
Still if you do get a small puncture, with run-flat tires you'll be able to continue on your way and won't be wrestling with a jack and a spare late at night or in an isolated area.
If you are buying a new car that doesn't come with a spare and you want one, ask. Sometimes dealers can sell you a traditional spare-tire kit. But make sure it is designed for your trunk and fits securely.
Spare tires becoming less common in new cars