Motor oil myth: How often should you get an oil change?

CHICAGO, IL -- It's a controversial question in car care: when to change your motor oil.

The I-Team is examining the motor oil myth and the conflicting information. You could be wasting money on unnecessary oil changes.

It's a question that may be driving you crazy. Which do you follow: the little sticker the mechanic puts on your windshield or the manual that comes with your car?

The I-Team did some digging to find out how you can save money. But first, we asked people on the street: how often do you really have to change your oil?

"Probably about 3,000 miles," one person said. "Because I actually look at the sticker that they put inside that tells you when you're due back again."

But you may not have go every 3,000 miles like that sticker on your windshield suggests.

"Like every 5,000 miles - that's what the recommendation is from the manufacturer," another person said.

Car makers' recommendations now vary by the type of car, type of oil and how you drive.

"I would absolutely go with the manufacturer," said Tom Appel, publisher, Consumer Guide Automotive.

In Morton Grove, Appel told the I-Team that there are several reasons for that advice.

"What's happened is oil has improved. Car engines have improved," Appel said. "And just the two things working together have meant that people can go longer without an oil change."

Appel said you should open your glove box and look at your owner's manual. He showed us one example for a 2016 Nissan.

"And they recommend 5,000 miles or 6 months for each oil change with no qualifications, so if you own that car, 3,000 miles is just a little bit too soon," Appel said.

ABC7's sister station in San Francisco took the same car to three different auto shops and got three different answers ranging from every 3,000 to every 10,000 miles.

The I-Team checked with the Illinois Automobile Dealers Association and the Chicago Automobile Trade Association. Both recommend following manufacturer guidelines which experts say keep you covered under your vehicle's warranty.

The CATA adds that: "For years, quick-lube oil change specialists have pushed the mentality that oil must be changed seasonably or every 3,000-3,500 miles. That's certainly not the case today, and likely never was."

"They are going to spend less money on oil changes and it's going to be better for the environment because we are not disposing of so much motor oil," environmentalist Mark Murray said.

The bottom line is: read your owner's manual. In newer cars, pay attention to warning lights that tell you when you need service. And if you've lost the manual, you can try to look it up online, call the manufacturer or get help from a service manager at a dealership.

READ: More tips from Automotive Maintenance Repair Association