CBS NEWS-- When you buy a new car you check out how it drives, the gas mileage, the bells and whistles.

One thing you're probably not checking for -- a spare tire. It should just come standard right? Not anymore. A new AAA survey found that 28% of 2017 models were sold without a spare tire as standard equipment.

But this isn't new, it started a few years ago. AAA says manufacturers wanted to make the car lighter and give it better gas mileage. Instead, they're putting tire inflation kits in the car, but that doesn't always do the trick.

“It won't work, this kit will not work, mainly because the puncture is too wide and the sealant will come right out the only option for this car was to get it towed - and you know that can get expensive.”

Last year AAA responded to 450,000 calls involving drivers who didn't have a spare.
The spare tire is now *optional on many new vehicles, so make sure before you buy your car that you ask if there's a spare tire.