2018 Sonata Transmission Fluid Change Interval?

ClearTheCode admin answer:

For your 2018 Hyundai Sonata SE, the transmission fluid maintenance is a common point of confusion. While some manufacturers label fluid as 'lifetime,' this often refers to the expected life of the original owner, not the vehicle's entire lifespan. Given your mileage and occasional towing, which falls under 'severe driving conditions' according to Hyundai's guidelines, a transmission fluid service is highly recommended.

Here's what you should know:

1. Check Your Owner's Manual: Always refer to your specific owner's manual for the most accurate service intervals. For severe driving conditions, Hyundai typically recommends inspecting or replacing automatic transmission fluid around 60,000 miles.
2. Drain and Fill vs. Flush: A 'drain and fill' replaces only a portion of the fluid (what's in the pan), while a 'flush' (or fluid exchange) replaces nearly all of it. For preventative maintenance, a drain and fill is often sufficient and less risky. A full flush should ideally be done by a professional using proper equipment to avoid potential issues.
3. Fluid Type: It's crucial to use the correct fluid. Your 2018 Sonata likely requires Hyundai SP-IV or an equivalent fluid that meets the SP-IV specification. Using the wrong fluid can cause transmission damage.
4. When to See a Shop: If you're unsure about the process, or if you notice any shifting issues, hesitation, or unusual noises, it's best to have a qualified technician perform the service. They can also inspect for any leaks or other potential problems with the transmission.