The 2015 Kia Optima uses different tire sizes depending on trim and wheel size: LX trims typically use 205/65R16, EX trims use 235/45R17, and SX trims use 235/45R18. Always verify the exact size shown on the door placard or in the owner's manual, especially if your car has aftermarket wheels or a different package.
Stock tire sizes by trim
Below are the typical OEM tire sizes associated with the main trims of the 2015 Optima. If your vehicle has nonstandard wheels or a factory option that differs from these, sizes may vary.
- LX: 205/65R16 (on 16-inch wheels)
- EX: 235/45R17 (on 17-inch wheels)
- SX: 235/45R18 (on 18-inch wheels)
Always verify the exact size on the door jamb placard and consult your owner's manual before purchasing tires.
How to confirm the correct tire size for your Optima
Use these steps to ensure you select the right tires for your specific car configuration and to avoid mismatched replacements.
- Check the driver’s door jamb sticker for the “Tire Size” entry; this shows the OEM size for your vehicle as it sits on your current wheels.
- Consult the owner’s manual or a dealer to confirm the recommended size for your trim and wheel package.
- Inspect the sidewall of your current tires for size markings (for example, 205/65R16 or 235/45R17) to confirm what you have installed.
- If replacing all four tires, aim to use the same size on all four corners; if you must mix sizes, keep the overall diameter within roughly 2-3% of OEM to preserve speedometer accuracy and handling.
- Ensure the replacement tires have an appropriate load index and speed rating that meet or exceed the OEM specification for your trim.
- Consider winter or all-season tires appropriate for your climate, and verify that any seasonal tires use the same size on all wheels.
Following these checks helps ensure you buy tires that fit correctly and maintain safe performance for your 2015 Optima.
Summary
For a 2015 Kia Optima, the typical stock sizes are 205/65R16 for LX, 235/45R17 for EX, and 235/45R18 for SX. Always confirm the exact size with the door placard or the owner’s manual, especially if your car has optional wheels or packages. When shopping, keep in mind the importance of consistent sizes across axles, appropriate load and speed ratings, and compatibility with climate (winter vs. all-season tires).