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The war in Iran has pushed up the price of crude oil and derivatives like gasoline, diesel and jet fuel — all of which have been making headlines for months.

But less has been said about the rising price of motor oil, the lubricant that protects your car's engine from wear and tear. Your next oil change could be quite a bit more expensive.

And even if the framework deal is signed this week, that problem isn't going away any time soon.

Since the start of the war, the price of the base oil used to blend widely-used synthetic motor oil has "more than tripled to record levels," Amanda Hay, an analyst with the market insight firm Independent Commodity Intelligence Services, told NPR via email.

While the U.S. is a net exporter of gasoline, diesel and jet fuel — producing more than we use — the country is a net importer of base oil. The oil used in synthetic motor oil, in particular, is not produced in the U.S. in large quantities.

Synthetic motor oil used to be a premium product that was mostly used by high-end vehicles, but increasingly, ordinary vehicles call for the higher-performing lubricant. Despite the word "synthetic" in the name, it's still made from crude oil or natural gas, but through highly sophisticated engineering processes that result in a thinner, longer-lasting oil. Most refineries simply can't do that kind of manufacturing.

In fact, Hay says the U.S. has the largest trade deficit in the world when it comes to "group III base oil," the type used for synthetic motor oils.

"We rely heavily on the Middle East," says Holly Alfano, the CEO of the Independent Lubricant Manufacturers Association. More than 45% of U.S. imports of group III base oil come from the Middle East.

That trade, of course, has been disrupted by the reduced traffic through the Strait of Hormuz. And even worse, the world's largest facility producing that type of oil — the Shell Pearl GTL plant in Qatar — was damaged by an Iranian missile in March. Half of its output is expected to be offline for at least a year, Hay says.

What about alternatives? Well, Alfano says, South Korea is also a major supplier of Group III base oil. "But unfortunately, right now, South Korea is dependent on crude from the Middle East," she notes.

Meanwhile, many U.S. refineries can produce less advanced "group II" base oils, which can be used to make conventional motor oil and in some cases could substitute for shortfalls in synthetic oils. But refineries essentially have to choose between making that lubricant or making diesel fuel. Diesel fuel is more profitable right now, so group II, too, is in "really short supply," Alfano says.

"It's a really sticky situation," she says.

If the Strait of Hormuz reopens, it should help restore supplies of base oil from South Korea. But the shutdown at Pearl and the economic pressure to prioritize diesel over lubricants are both expected to continue into next year. And while the U.S. does have some new plants under construction that will produce more group III base oil, they aren't set to open until 2027 or 2028.

"Fewer, more expensive choices seem like the likely outcome," Hay says.

Prices for lubricants soar 

But that's not the same as an outright shortage, where drivers can't get oil at all. Hays says supply "gaps" are likely, and the biggest squeeze will be for motor oil that is associated with specific automakers, carrying their branding.

Across the market, though, higher prices are likely. Since the war started, the industry has been relying on inventories — stockpiles of base oil — which has helped cushion the blow for retail customers. But those stockpiles are now running out, Alfano says.

While the full price hike hasn't trickled down to drivers just yet, mechanics are starting to feel it.

"We've now seen oil, just regular motor oil, go up in price by 60%," says Nathan Matheson, who owns Nathan's Small Engine Repair and Automotive Services in Poolesville, Md. He's holding his oil change prices steady, absorbing the rising cost as a blow to his margins — for now.

And the real problem, he says, is that this is coming on top of all kinds of other rising costs driven by President Trump's tariffs. While the Supreme Court lifted tariffs on many goods, ruling that the executive order used to impose them was unconstitutional, tariffs on auto parts were enacted under a different authority, and remain in place.

"A lot of common consumable parts, from oil filters to brake pads to belts, have been significantly increased in costs as a result of the tariffs," Matheson says. That's pinching both mechanics and drivers.

Onur Azeri, who manages a specialty mechanic shop in Sonoita, Ariz., agrees. "Don't get me wrong, motor oil is important," he says. But, he adds, "I'm way more concerned, my clients are way more concerned, about the cost of parts." And that's not to mention the daily burden of higher gasoline and diesel prices.

Matheson says his customers are driving less overall, with some switching to commuting by electric bikes to save mileage on their cars. He's also hearing more and more from drivers eager to postpone whatever auto repair work they can. "The first question is: What do I really have to do? What can I wait on, what is important?" he says.

It's a dilemma Matheson understands well. In fact, for more than two years he's put off replacing the head gaskets on the Subaru Outback he uses as a company car, hoping that component costs would come down.

They never did, so he finally bit the bullet. When he spoke to NPR, his Subaru's engine was behind him in pieces, partway through the repair.

What can drivers do? 

First, Alfano recommends that drivers check their vehicle's manual to see what kind of motor oil the manufacturer recommends. Make sure to follow those guidelines, she says. In some cases, there may be substitutes that fit within the performance standard required for your car, but don't just put in a cheaper or more readily available oil without checking.

And, she says, the old recommendation to get an oil change every 3,000 or 5,000 miles is dated. If you're paying a premium for a high-end synthetic motor oil, you should be getting a lot more miles between oil changes; check your manual for guidance on that, too.

For maintenance and repairs in general, Matheson urges everyone to shop around for multiple opinions. Ask each mechanic who looks at your vehicle which work is actually essential.

But be careful about putting off work for too long.

Matheson has had customers come in for major engine repairs that could have been avoided with preventative maintenance. "Instead of spending $160 to change your four-wheel drive transfer case fluid, they're not doing it," he says. "And then it turns into close to $2,000 part component replacement."

"If you need something," he says, "you need it."