Creates an electrical spark that ignites the compressed air-fuel mixture in each cylinder, initiating the combustion process that drives the pistons and powers the engine.
$100 – $350
Total Cost
30,000 – 100,000 miles
Replace Interval
Moderate
DIY Difficulty
Schedule Soon
If It Fails
Spark plugs ignite the air-fuel mixture in your engine's cylinders, creating the controlled explosions that power your car. They're one of the most commonly replaced engine components and a key part of routine maintenance.
Parts Cost
$20 – $200
Labor Cost
$40 – $150
Replace at your manufacturer's recommended interval, or immediately if you're experiencing misfires. Don't wait for symptoms — worn spark plugs reduce fuel economy by 10-30% even before they cause noticeable issues.
German turbocharged engines typically need spark plug replacement every 30,000-40,000 miles — more frequently than naturally aspirated engines.
Ford's 5.4L 3-valve V8 (2004-2010) is notorious for spark plugs breaking during removal. Use anti-seize and the correct removal procedure.
Always consult your vehicle's service manual for model-specific procedures. If you're unsure, have a professional do the work.