5 Things to Know About Oil Changes for Your Car
Understand when and how often to change it, what type your car needs, and more
Even as cars become increasingly sophisticated, motor oil remains the engine’s lifeblood, and caring for this fluid is vital. Fortunately, this is a rather simple task—and your car’s onboard computer can help.
1. When to Change the Motor Oil
It needs to be changed when it’s either worn or aged out. The oil degrades from heat and pressure, and it collects harmful particles that need to be removed. Plus, oil breaks down over time, even when a car is parked for an extended period.
2. How Often to Check the Oil Level
Our mechanics recommend checking at least once a month or ideally every other gas fill-up. Don’t assume that a new car is exempt from this maintenance chore. Consumer Reports reliability survey results have shown that even newer cars can need the oil to be topped off between changes.
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. Our mechanics warn that the amount of oil left in some engines by the time an alert comes on can be shockingly low.
Photo: iStock Photo: iStock
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. Most automakers recommend checking the oil level when the engine is cool.
With the engine off, open the car’s hood and find the dipstick. Pull it out from the engine and wipe off any oil from its end with a dust-free cloth or towel. 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’s 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.
If the oil is below the minimum mark, you need to add oil. (Use the oil type recommended in the owner’s manual, adding no more than half a quart at a time. Let the car sit, then check again.)
Pay close attention to the old oil’s color. It should appear brown or black. If it has a light, milky appearance, this could mean coolant is leaking into the engine. Look closely for any metal particles, too, because this could mean there’s internal engine damage. If you see either of these conditions, take the car to a mechanic for further diagnosis.
If everything is okay, wipe off the dipstick again and insert it back into its tube, making sure it’s fully seated. Close the hood and you’re done.
If the oil is consistently low when checked, the engine is either burning the oil or leaking it. Either way, discuss this recurring problem with your mechanic.
3. How Often to Change the Motor Oil
The “every 3,000 miles or every three months” rule is outdated because of advances in both engines and oil. Many automakers have oil-change intervals at 7,500 or even 10,000 miles and six or 12 months.
“Your owner’s manual has more detailed information about your car than any mechanic does,” Ibbotson says. “Don’t get talked into too-often oil changes. Follow the manual and your car’s engine should stay well-lubricated and perform wel
Photo: Getty Images Photo: Getty Images
Over the course of two years and 30,000 miles, assuming that your oil change costs $90 a pop, you could save $540 if you get it changed every 7,500 miles vs. every 3,000 miles—plus a fair bit of time.
It’s not just about miles: If you don’t drive your car a lot, your oil still needs to be kept fresh. Even if you drive fewer miles each year than your automaker suggests for changing the oil (say, 6,000 miles, with suggested oil-change intervals at 7,500 miles), you should still be getting that oil changed twice a year.
Why? Oil becomes less effective as it ages, and by not getting the engine warm enough, excess contaminents that collect in the engine won’t be removed, which can lead to a shorter engine life.
Go to our guide to car maintenance and repair.
4. Choosing the Right Oil for Your Car
Again, take a look at your owner’s manual. “Don’t be upsold into synthetic oil if there is no need,” Ibbotson says.
In many newer models, the weight of the car’s motor oil is printed on the cap where you add oil, and it’s listed in the maintenance section of the owner’s manual. “Make sure you know what’s recommended or required by your automaker before you visit your mechanic so that you can control the cost of the oil they’re putting in,” he says.
Photo: John Powers/Consumer Reports Photo: John Powers/Consumer Reports
If you have a much older car, do you need special motor oil?
“Not if it’s running well,” Ibbotson says. “If you’re not sure what oil you should be using because you don’t have an owner’s manual, check with your local dealer or an online enthusiast group for your particular model.”
Don’t get creative with your engine oil choice. The automaker spent many millions of dollars to develop the engine, and it chose the recommended oil for a reason.
When changing the oil, be sure to use an original equipment or premium-grade oil filter rather than a budget filter.
5. Does Your Car Need Synthetic Oil?
“Only if your manufacturer calls for it,” Ibbotson says, “because it can cost from two to four times as much as conventional oil.” He adds that most recent models use synthetic.
Synthetic oil is designed to be more effective at resisting breakdown (and because of that, it lasts longer) and withstanding high temperatures.
Photo: Getty Images Photo: Getty Images
But he advises that there are situations where that resistance to breaking down can help prolong the life of your engine, making the upgrade from conventional oil worthwhile.
“If you make lots of short trips, standard motor oil may never get warm enough to burn off moisture and impurities, which means it may not be doing enough to protect your engine,” Ibbotson says.
Another consideration is your lifestyle. “If you live in a region with very cold winters or very hot summers, or if you use your vehicle for towing or hauling heavy material, synthetic oil is your best bet,” he says. “While synthetic generally holds up better and can serve for more miles, it is equally important to not extend oil changes beyond the time interval recommended by the manufacturer, typically six months or a year if it is a motor that is not driven many miles or on many short trips.”
Synthetic oil can also help engines that are prone to building up sludge. Some Volkswagen and Toyota models had sludge issues in the past. This residue, formed when oil breaks down, can block the flow of oil, leading to the quick death of an engine. Synthetic oil would be beneficial in these engines because it helps to reduce sludge buildup, helping to extend the engine’s life span.
