Some automotive maintenance myths seem to have taken on lives of their own. Sure, they seem like logical, sound pieces of advice, but when it comes to maintaining your car, they could end up costing you extra money and time in the long run.

Here are seven common car care myths and some pitfalls to avoid when taking care of your vehicle. 


Myth: Tires should be inflated to the pressure embossed on the tire’s sidewalls.
Reality: That figure is the maximum pressure—not necessarily the ideal pressure.

What you should do instead: Always go by the vehicle manufacturer’s recommended pressure, which is usually printed on a sticker on the driver’s doorjamb or inside the fuel-filler door.

“This pressure is what the manufacturer has determined to provide the best balance of ride, handling, and fuel economy for your vehicle,” says Gene Petersen, who runs the tire testing program for Consumer Reports. “If you inflate the tires to the maximum pressure, you may end up wearing them unevenly, and you’ll likely need to replace them sooner.”

To keep your tires in tip-top shape, check their pressure monthly; if you can, do it early in the morning while the tires are cold. Otherwise, make sure the car has been at rest for at least 3 hours, and out of the sun.

Read "Choosing the Best Tire Pressure Gauge."


Myth: If regular-grade fuel is good, premium fuel must be better.
Reality: Most vehicles are designed to run just fine on regular-grade (87 octane) gasoline, and filling up with a higher grade is a waste of money. “A higher octane number doesn’t mean that your vehicle will perform better,” said John Ibbotson, chief mechanic for Consumer Reports. “It simply means that it’s more resistant to engine knocking or pinging.”

What you should do instead: Use the octane grade that’s recommended in your vehicle’s owner’s manual. Still don’t believe us? We put this to the test at CR’s Auto Test Center.

Read "Study Shows Top Tier Gasoline Worth the Extra Price."

Myth: Don’t worry about replacing tires until they’re down to the minimum tread depth.
Reality: It’s true that it's time to replace a tire when its tread wears to the minimum depth of 2⁄32 inch in most areas. But if you wait until then, you are putting yourself at risk. “At the very low 2⁄32-inch tread depth, a tire’s wet grip, snow traction, and ability to resist hydroplaning is very limited,” says Petersen.

What you should do instead: According to Petersen, “Start shopping for replacement tires before yours are worn out.” At 4⁄32 inch, tires still have some all-weather grip, which leaves you time to shop around for the best tire at the best price. In addition, it’s best for optimum handling and grip to replace tires in sets of four; you'll get the most life out of your tires if you rotate them following the schedule in your car's owner's manual.  

Learn more in our tire buying guide


Myth: Let your engine warm up for several minutes before driving.
Reality: That might have been good advice once, but modern engines warm up more quickly when they’re actually being driven.

What you should do instead: Get in, start the car, and start driving. The sooner the engine warms up, the sooner it reaches its maximum efficiency and delivers the best fuel economy and performance. But don’t rev the engine high over the first few miles while it’s warming up.


Myth: A dealership must perform your car’s regular maintenance to keep your factory warranty valid.
Reality: As long as the maintenance items specified in the vehicle owner’s manual are performed according to the recommended schedule, the work can be done at any trusted auto-repair shop.

What you should do instead: If you don’t have a trusted mechanic, ask co-workers or friends to recommend one. You can even do the work yourself if you have the tools and the knowledge. Keep accurate records and receipts to back you up in case of a warranty dispute. The only time you must take your car to a dealer is to have recall work performed. Read more about recalls on our Car Safety hub.


Myth: Special service is required to “winterize” or “summerize” your car.
Reality: There isn’t anything special that you need to do to your car when the seasons change.

What you should do instead: If you keep up with the scheduled maintenance, you don’t need to perform any seasonal service, Ibbotson said. Moreover, today’s vehicles come with a “long life” coolant that can last up to 100,000 miles—but check your owner’s manual to see when the manufacturer recommends replacing it. In addition, modern air conditioning systems don’t require a “recharge” unless there is a problem with the system. If there is, it’ll usually take more than a recharge to fix it.


Myth: You need to diligently change your engine oil every 3,000 miles.
Reality: Although oil companies and quick-lube shops like to promote this idea, it’s usually not necessary. Most vehicles driven under normal conditions can go 7,500 miles or more between oil changes.

What you should do instead: Go by the recommended oil-change schedule in your owner’s manual. “Nearly all new models have a monitoring system that alerts the driver when the oil needs changing,” said Ibbotson. Depending on driving conditions, these can extend change intervals to 10,000 or 15,000 miles. Changing the oil more often is just pouring money down the drain.

Read "5 Things to Know About Oil Changes for Your Car."