Stu writes: I have a 2018 Kia Niro PHEV (plug-in hybrid electric vehicle) with 72,000 miles on the odometer. We bought it used from a Kia dealer, as it had been a lease car. The maintenance schedule calls for oil changes every 7500 miles, but since we are not the “average” user, it doesn’t make sense. Most of our use is electric-only: My wife and I are retired so there’s no work commute, just grocery runs and other errands. Most days we stay within the 26-mile, electric-only use. Several times a year we drive to and from a vacation place, about a thousand miles per round trip with the drive and errands there. We use an average of 10 gallons of gas every month or two. Our son-in-law is an electrician and installed a fast charger at home so a full recharge is only about two hours. At our vacation place, we plug into a 120v source and the recharge time is seven hours if the battery is near empty. There is no way to really measure engine mileage. I use a full synthetic oil of the correct viscosity, the car is garaged at home and under cover the rest of the time. I have been changing the oil once a year…is that enough or am I wasting good oil? Sajeev answers: Stu, odds are the annual oil changes are just fine, as your internal combustion engine (ICE) can be treated like one in a classic car being stored for the winter. This conclusion comes from the fact that my research suggests the Niro doesn’t have an oil life monitor that calculates oil degradation. Instead your system is reset with every oil change, hence the factory recommendation of 7500 miles between oil changes. While the correct answer is to have an oil sample analysis after your next oil change (as disussed here) the gasoline engine in your PHEV isn’t under the same loads as a conventional ICE car. It sounds like the engine will rarely be used in your vehicle, and there is a good chance that Kia’s tuning includes periodic engine running to burn off excess moisture. I think we are splitting hairs in your situation. Annual oil changes are great for reducing the potential risk of engine wear, but we might have another issue. If you are always charging the Niro’s battery to 100 percent, but seldom take it on long journeys soon afterwards, you might be shortening the lifespan of its lithium-ion polymer battery. Keeping many (but not all) lithium-ion based batteries in a 20-80 percent range can extends the useable life. While I have no idea how to make that happen for you, there might be a smartphone app that monitors battery charging remotely for you. It’s probably never too late to start charging to 80 percent, as it can reduce the frequency of cycles the gas engine is called into duty. If you use synthetic oil changed annually, your PHEV will be ready for anything, even as the battery degrades over time and mileage. These vehicles are perfect for many use cases, so I wish you nothing but the best of motoring with this Kia Niro. Have a question you’d like answered on Piston Slap? Send your queries to pistonslap@hagerty.com—give us as much detail as possible so we can help! Keep in mind this is a weekly column, so if you need an expedited answer, please tell me in your email. Looking to purchase a car? Find your match on the MSN Autos Marketplace
Liked by Owen Fortin, Lucas Wright
Liked by Owen Fortin, Lucas Wright
Liked by Owen Fortin, Lucas Wright
