Some Newer Cars Can Burn Lots of Oil

A CR autos editor discovered that his used Subaru suffers from a documented oil-burning problem. How to identify the problem in newer cars and what to do about it.

Last summer the time came, finally, to say farewell to the 33-year-old station wagon I’d been driving for ages. I replaced it with a 2015 Subaru Forester—a good all-around family vehicle with a solid safety and reliability track record. It was new enough—it had well under 100,000 miles on it—so I didn’t expect to hover over its vital functions the way I had with my ancient, smoke-belching wagon. But I was wrong. After a couple of months, the low-oil-level light came on. The SUV had burned almost 2 quarts of oil over just a few thousand miles.

With a big, rusty 1970s sedan, I might have expected a cloud of blue-tinted oil smoke in my wake, along with a wad of prehistoric cigarette butts in the ashtray. But the Forester was a modern car, built in an era when automotive engineers had supposedly fixed such problems. I did some digging and found that not only was the model prone to oil consumption issues, but also there were other newer Subaru models and newish ones from other manufacturers that chronically burned oil, including several expensive BMW models equipped with 4.4-liter twin-turbo V8 engines.

Consumer Reports exposed this problem several years ago, with most manufacturers we mentioned having since worked to fix the problems. Even so, recent CR reliability data show that there are still models, some only a few years old, that can burn enough oil to deplete the engine of what it needs for lubrication between factory-recommended oil changes, which can be up to 10,000 miles, depending on the model. And with the average age of cars on the road up to more than 12 years, these oil-burners are likely to pop up in a consumer’s search for a used car.

After all, I ended up with one, and it’s my job to know a lot about cars.

CR believes that people who drive modern cars shouldn’t have to worry about running low on oil and having to routinely top it off between scheduled service visits. And because many car owners don’t check their oil anymore, oil burning can be a big problem in the few cars with this antiquated malady.

“Nobody really expects that they’ll have to check the oil on a regular basis, and with service intervals so far apart, it’s possible that someone could run the oil sump dry and cause major damage to the engine,” says John Ibbotson, CR’s chief mechanic.

In all, CR’s survey identified problem engines produced by eight manufacturers, some of which—including, fortunately for me, Subaru—agreed to extend factory warranties amid class-action lawsuits. For others, it’s very much a “buyer beware” scenario. Do your research. Long factory-recommended oil change intervals—6,000 miles between oil changes for a Subaru, and 10,000 for a BMW, for example—mean that even a small or moderate rate of oil consumption can cause expensive damage inside the engine and the catalytic converter before the oil is changed and refilled.

CR contacted all the manufacturers with oil-burning engines identified in our survey. Most provided CR with a list of the models prone to oil consumption and gave advice for consumers who have experienced the problem. Several of the manufacturers already had taken action to correct oil-burning in their cars. General Motors, for example, responded to complaints about oil-burning in the 2.4-liter four-cylinder engine the company used in a number of Chevrolet Equinox and GMC Terrain SUVs by extending the factory warranty to more than 100,000 miles. After a class-action lawsuit, Subaru did the same for certain models from the early to mid-2010s, offering oil consumption tests and, if necessary, engine replacements. While this is a good move by the automakers, shoppers need to be aware of this risk when considering a high-mileage car that would be out of scope for even a warranty extension.

Read on to learn whether your car might be one of the oil-burners. Responses from the manufacturers of each affected engine are listed toward the end of the article.

Photo: iStock Photo: iStock

Chuck Lynch, director of technical services at the Automotive Engine Rebuilders Association, says oil consumption problems, all but eradicated by most manufacturers by the early 2000s, began to appear again toward the middle of the decade, after federal fuel-economy standards became more demanding. That’s when manufacturers began making trade-offs in engine design that would increase efficiency but in some cases had an adverse effect on durability. The irony, he says, is that more significant fuel-economy gains came not from engine design changes but from using more advanced eight-, nine-, and 10-speed automatic transmissions to help keep engines in the optimal rpm range.

“The manufacturers write the rules on what’s acceptable when it comes to oil consumption,” Lynch says. “There’s no government standard on oil consumption, or how much oil an engine of a given displacement needs to have in its sump.”

Subaru had designed my car’s 2.5-liter four-cylinder engine for better fuel economy, but the way the pistons and piston rings were set up allowed oil from the crankcase to slip past the pistons into the combustion chambers, where the pistons compress and ignite the fuel-air mixture to create the power needed to turn the crankshaft and move the car. In the wake of the class-action lawsuit, Subaru extended the factory warranty (previously five years or 60,000 miles) to eight years or 100,000 miles, whichever comes first. Honda and GM have made similar concessions for oil-burning engines installed in vehicles they sold, including certain 2009 to 2014 Acura vehicles equipped with a 3.7-liter V6, and 2010 to 2013 Chevrolet Equinox and GMC Terrain SUVs equipped with a 2.4-liter four-cylinder engine.

I took my SUV to the dealership for an oil consumption test. The mechanics changed the oil (at my expense), sealed the dipstick shut with a zip tie, and marked the oil fill cap, oil pan drain plug, and oil filter with paint to ensure that they wouldn’t be tampered with. They checked the oil level again after 1,200 miles. The results were dismal—it had used almost 2 quarts. So Subaru of America gave the approval for the dealer to install a new engine in my SUV, free of charge. (However, even that engine came with its own set of problems, and it took a significant amount of my time shuttling back and forth from the dealership service department to have them resolved.)

Not everyone is so lucky. Some automakers say vehicle owners are responsible for routine oil level checks, and may leave customers to fend for themselves if an engine ends up burning a lot of oil. The best way to guard against oil consumption, though, is to rely on cars that don’t burn oil. We said it in 2015, and we’ll say it again: Newer cars shouldn’t burn oil.

“We’re going to be hard-pressed to convince society to go back to checking the oil every time you get gas,” Lynch says. “Most people just aren’t in the habit of doing it anymore."

This oil-burning problem is compounded because auto regulators don’t consider it to be a safety concern, so they don’t require automakers to address it through recalls. And the old litmus test for burning oil—blue exhaust smoke—doesn’t apply for newer models because advanced catalytic converters mask the problem. As a result, a newer car might quietly burn oil and an unsuspecting owner could end up with major repairs, including compromised catalytic converters or a damaged engine.

“It always astounds me how they don’t recall these things,” says Jill Trotta, vice president of industry and sales at RepairPal and an ASE-certified technician with 30 years of experience. “They don’t have to because it’s not a safety issue. They can put out a technical service bulletin (TSB), so there can be some assistance, but that doesn’t really fix the problem.”

TSBs are communications from automakers to dealers alerting them about potential problems with vehicles, and they often contain special service instructions or procedures for dealer technicians. A TSB falls short of a recall, which usually relates to safety concerns and triggers an aggressive campaign to correct the problem at no cost to the owner. Quite often, car owners are unaware that TSBs exist or that there might be a known problem with their car.

“If you suspect your car is burning oil, checking the oil level on a regular basis is a good place to start,” Ibbotson says. “Then it’s time to start asking questions at the dealership to see if you qualify for any corrective action at the manufacturer’s expense.”

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