When Should You Replace Spark Plugs?
Spark plugs ignite the fuel mixture. Worn plugs weaken combustion and cause misfires and higher fuel use — and their change interval depends on their type.
Types and intervals
Copper plugs last less, while platinum and iridium last much longer. The exact interval is in your manual — do not rely on a generic number.
Wear signs
Hard starting, rough idle, hesitation on acceleration, higher fuel use, or a misfire code (P0300/P030X). See the P0300 guide.
Tips
Replace them as a full set, with the recommended type/gap. Track the odometer since the last change. Mowtar AI logs them and reminds you from your history.
FAQ
Are pricier plugs always better?
Not necessarily — best is the type your manufacturer recommends (copper/platinum/iridium) with the correct gap.
New plugs but still stumbling?
Could be coils, ignition wires, or another cause — read the codes via OBD2.