When doing replacement or upgrading on 2017 – 2018 Hyundai Ioniq with capsule halogen headlamps HID, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

• Hyundai Ioniq with halogen capsule headlamps Bulb Size Guide
• Hyundai Ioniq with HID headlamps Bulb Size Guide

2017 – 2018 Hyundai Ioniq with halogen capsule headlamps Bulb Size Guide
Low Beam Headlight	2017 – 2018	H7
High Beam Headlight	2017 – 2018	9005
Back Up Light	2017 – 2018	921
Brake	2017 – 2018	1157
Dome Light	2017 – 2018	DE3175
Front Side Marker	2017 – 2018	168
Front Turn Signal	2017 – 2018	2357NA
License Plate	2017 – 2018	168
Parking Light	2017 – 2018	168
Rear Side Marker	2017 – 2018	168
Rear Turn Signal	2017 – 2018	1156
Tail Light	2017 – 2018	1157
Trunk	2017 – 2018	DE3423

2017 – 2018 Hyundai Ioniq with HID headlamps Bulb Size Guide
High Beam and Low Beam Headlight	2017 – 2018	D3S
Back Up Light	2017 – 2018	921
Dome Light	2017 – 2018	DE3175
Front Side Marker	2017 – 2018	194
Front Turn Signal	2017 – 2018	2357NA
License Plate	2017 – 2018	168
Trunk	2017 – 2018	12844