HONOLULU (KHON2) -- In the last week, the Honolulu Fire Department responded to at least four vehicle fires on Oahu's major highways. Data showed two were on H3 and two were on H1. Download the free KHON2 app for iOS or Android to stay informed on the latest news After seeing multiple fires on highways this past month, KHON2 looked into the numbers and found that HFD responded to at least 15 vehicle fire calls on H1, Moanalua Freeway, Likelike and H3 since Oct. 1. KHON2 asked a mechanic why it seems to be happening so often. Investigation into deadly car fire near Harano Tunnel ongoing "The valve gasket tends to dry out and get old after a few years, they leak oil and the oil drips onto the exhaust and if there's enough oil, it will catch on fire," Won Pak, owner and partner at Punahou Auto Service explained as one of several reasons car fires happen. "Fuel injectors can leak, the fuel rail can cause fires mostly in older cars." According to HFD, there have been more auto fires on highways, residential, commercial and vehicle parking areas than the year before. Data shows from Nov. 18, 2022, to Nov. 17, 2023, there were 63 fires on highways, 69 on residential roads/streets/driveways, 21 in commercial areas and 24 in vehicle parking areas. From Nov. 18, 2023, to Nov. 17, 2024, there have been 74 fires on highways, 72 on residential streets/roads/driveways, 36 in commercial areas and 35 in vehicle parking areas. HFD added vehicle fires could include backhoes, cranes, motorcycles, mopeds, scooters and similar equipment. Pak said 74 fires on a highway was a lot, and KHON2 asked why so many on our busiest roads. West Oahu firefighters keep busy battling brush, truck fires "The faster the car is going, you add more pressure on the lines, there is more fuel coming in, and your engine oil would be leaking faster if you had a leak," explained Pak. "The faster the car goes, the faster it leaks." HFD said it only investigates vehicle fire causes when there is a death or if they're asked by Honolulu Police. They added causes tend to be a mix of intentional and accidental - which often includes, but is not limited to, vehicle recalls, user neglect or mechanical failures. Mechanics said fuel and oil are the common causes of fires, and older cars should be getting routine maintenance done especially if the check engine light is on. "Normally, the gaskets dry out after six years, and then maybe it will start leaking a year after so maybe after 10 years you should have the gasket looked at routinely," he explained. Pak said customers often tell him they don't have time to get maintenance done or the money, but he says once a fire takes over the engine, the car is destroyed. Check out more news from around Hawaii "I've seen cars come in with no oil in the engine and that friction would also start a fire if you drive it long enough," Pak added. He said annual safety checks can help avoid a fire and encourage people to get their cars checked once that engine light pops up.