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If you’re confused about motor oil—the right time to change it, how often to change it, what’s the best oil for your car—Consumer Reports’ chief mechanic, John Ibbotson, can set you straight.
1. When to Change the Oil
The answer to a lot of these questions is the same: Check your owner’s manual. It should be your car maintenance and operation bible. Don’t make assumptions on the interval based on past experiences or guidance from mechanics who profit from the work, because the timing has evolved over the years.
Many cars, pickups, and SUVs now have service reminder monitors that alert drivers when to change their oil. “These systems typically monitor the number of miles a vehicle has traveled, and they also sense how hard the car is being driven, and adjust accordingly,” Ibbotson says.
Make sure you get your oil change soon after you receive such an alert.
2. How Often to Check the Oil Level
You should keep an eye on your car’s oil levels. Our reliability survey results have shown that even newer cars can need the oil to be topped off between changes.
CR recommends checking your oil level at least once a month. Be sure to get repairs done at the first sign of a leak.
Check the owner’s manual and follow the automaker’s recommendations. Some newer cars have electronic oil monitors and don’t have traditional dipsticks for manual inspection.
If you do have a dipstick, and you’re checking it yourself, make sure the car is parked on level ground. If the engine has been running, be aware of potential hot spots under the hood.
With the engine off, open the car’s hood and find the dipstick. Pull the dipstick out from the engine and wipe any oil off from its end. Then insert the dipstick back into its tube and push it all the way back in.
Pull it back out, and this time quickly look at both sides of the dipstick to see where the oil is on the end. Every dipstick has some way of indicating the proper oil level, whether it be two pinholes, the letters L and H (low and high), the words MIN and MAX, or simply an area of crosshatching. If the top of the oil “streak” is between the two marks or within the crosshatched area, the level is fine.
But if the oil is below the minimum mark, you need to add oil.
Pay close attention to the oil’s color. It should appear brown or black. But if it has a light, milky appearance, this could mean coolant is leaking into the…