1 - Unleaded petrol: 1.0-1.1 mm
2 - Leaded gasoline: 0.7-0.8 mm
The spark plugs must be replaced at the intervals specified in the periodic maintenance chart in the Service Booklet or when engine operation requires it. Signs of poor spark plug performance include misfiring when the engine is running under load, decreased fuel economy, poor acceleration, etc. When replacing the spark plugs, use only the spark plugs recommended by HYUNDAI. Using other spark plugs may result in poor engine performance, radio interference, or engine damage.
Note: When replacing spark plugs, use only genuine spark plugs recommended by Hyundai.
Recommended spark plugs:
| Undiluted gasoline | Leaded gasoline | |
| CHAMPION | RC10YC4 | RC10YC |
| NGK | BKR5ES-11 | BKR5ES |
Replacing spark plugs
It is recommended to replace spark plugs on a cold or cooled engine. Replace spark plugs one at a time, this will help to avoid incorrect wiring.
1. Remove the cylinder head center cover (1.6L engine only),
2. Using a clean cloth, remove any dirt from around the spark plug that may enter the engine cylinder through the spark plug hole.
3. To disconnect the spark plug wire, pull the connector parallel to it. Do not pull on the spark plug wire, this may damage it.
Warning: It is recommended to replace spark plugs on a cold or cooled engine. If the engine is hot, you may burn yourself on hot engine parts or spark plugs.
4. When removing the old spark plug, be careful when placing the spark plug wrench on the spark plug to avoid damaging the ceramic insulation.
5. To remove the spark plug, turn the spark plug wrench handle counterclockwise.
6. When installing a new spark plug, be careful when placing the spark plug wrench on the spark plug to avoid damaging the ceramic insulation.
Note: It is important to tighten the spark plugs securely. Overtightening the spark plug can damage the threads in the aluminum cylinder head. Overtightening the spark plugs can cause excessive spark plug heat and possible engine damage.
7. Install the high-voltage wire directly onto the electrode. Make sure it is securely fixed and will not fall out.