tech
February 11, 2026
From Bad Starts to Increased Consumption: How Spark Plugs Affect Your Car and Why It's Important to Change Them Regularly
The spark plug plays a key role in the functioning of a gasoline engine, and Marin Morava, technical advisor at HAK, writes about its importance, replacement, and most common problems. Its primary function is to ignite the fuel-air mixture by creating a high-voltage spark between electrodes. During engine operation, a spark plug can ignite the mixture up to 500, or even 3,500 times per minute. When functioning correctly, it ensures easier engine starting, smooth and efficient operation, lower fuel consumption, and reduced emissions of harmful gases.
TL;DR
- Spark plugs ignite the fuel-air mixture, influencing engine starting, efficiency, fuel consumption, and emissions.
- Problems like rough idling or reduced power can indicate faulty spark plugs or incorrect installation.
- Spark plug replacement intervals vary from 20,000 to 120,000 km, depending on the type.
- Correct spark plug selection requires matching the vehicle's specifications, including thermal value, to ensure optimal operating temperature.
- Improper DIY replacement can lead to engine damage or electric shock.
- Regular visual inspection and professional diagnosis can identify spark plug issues or other engine problems.
- Failure to replace spark plugs can result in costly engine damage, such as the insulator breaking and falling into the cylinder.
- Regular maintenance and timely spark plug replacement are cost-effective compared to engine repairs.