Why It Suddenly Costs So Much More to Own a CarAutoweekJim MotavalliTue, September 22, 2026 at 2:10 AM UTCAdd us on GoogleWhy It Suddenly Costs So Much More to Own a CarKevin Carter - Getty ImagesDid you buy motor oil at Costco recently? You may have noticed that, right after Labor Day, the price of 10 quarts of full synthetic motor oil went from $30 to more than $57. Talk about sticker shock. The bottom line may actually be higher now: At Walmart, five quarts of Valvoline 5W-30 full synthetic was $35.97 on September 18. And that's just the start when it comes to a rising cost of car ownership, largely caused by inflation and the Iran war.At a Cleveland shop, Terry's North Coast Auto Repair, manager William Robinson reports prices for motor oil rising 25 percent. "An oil change is not the highest profit margin," he told WKYC television. "If prices do continue to increase and we can't ride that out, of course small shops like ours would have to hand the price down to customers."The culprit is not hard to find. According to global consulting firm Ducker Carlisle, approximately 44 percent of the Group III base oil that is refined into synthetic for the US market comes from the Middle East, where deliveries are hung up in the Strait of Hormuz. Shell's refinery in Qatar is part of the collateral damage. A fifth of the world's oil (20 million barrels a day) normally passes through the Strait, but right now that traffic is down 95 percent, from 100 to 125 tankers daily to five to 14 ships.Crude oil offloaded to trucks at the Banyas Oil Terminal in Tartus, Syria, on September 13.Anadolu - Getty ImagesA gallon of regular gas was an average of $4.47 across the US on September 18. A barrel of oil on the global spot market is now $100.17, with Brent Crude trading at $103.69.AdvertisementAdvertisement"The Iran war caused a spike in fuel prices," Nate Chenenko, a principal at Ducker Carlisle, told Autoweek. "This affects every supply chain—most were optimized around $4 per gallon diesel. Now that diesel is over $6 per gallon, companies should be considering a re-think of their supply chains. Offsetting slower inbound transportation with slightly higher inventories is the core to the solution."Gas prices are displayed at a Pilot gas station on September 17 in Newark, New Jersey.Michael M. Santiago - Getty ImagesIt's not just motor oil—there's the whole vehicle to consider. The average new car transaction price in August, according to Kelley Blue Book, was a whopping $50,089, up from $49,275 in March.Many auto parts use petroleum as a base. Heather Long, a chief economist at the Navy Federal Credit Union, told CBS News that "the rising cost of car ownership has been the big shocker of the inflation crisis." A study by the union found that the cost of owning a car has risen a shocking 50 percent since 2020. The cost of car repairs is up 70 percent over the last five years, the union's study said. Insurance is up, too, and Americans are paying an average of $2,124 per year in 2026.There are a number of reasons why auto part prices are soaring, starting with the fact that much of their makeup—plastics, rubber, lubricants, and synthetics—are heavily reliant on oil in their component parts. According to a Roland Berger analysis, blockages in petrochemical production and distribution could raise the cost of car-related plastics and chemicals between 15 and 25 percent. A standard vehicle has between 330 and 440 pounds of petrochemical-derived plastic parts, Automotive News said.A standard vehicle has between 330 and 440 pounds of petrochemical-derived plastic parts.picture alliance - Getty ImagesThe Middle East also supplies 10 percent of the world's aluminum, with the US (which imports half its supply) a major customer. And aluminum prices have reached multi-year highs. There's also the fact of much higher shipping costs, and government tariffs on imported parts.With no end to the war in sight, car ownership is likely to remain expensive for a while.