What is the best mileage interval for replacing Focus spark plugs?
2 Answers
There are four points to determine whether Focus spark plugs need to be replaced based on mileage: 1. Copper core should be replaced every 20,000-30,000 kilometers. 2. Nickel alloy core should be replaced every 40,000-60,000 kilometers. 3. Platinum core should be replaced every 80,000 kilometers. 4. Iridium core should be replaced every 100,000 kilometers. The following is an introduction to the structure of spark plugs: 1. Steel shell: The lower part of the steel shell has fine threads for installation in the cylinder head spark plug hole, and the upper part has an external hexagonal nut for installing a spark plug socket to tighten or loosen the spark plug. 2. The metal rod is the center electrode. The lower end of the metal rod contacts the upper end of the center electrode through conductive glass, and the upper end of the metal rod is equipped with a terminal nut. 3. There is high-alumina ceramic insulation between the steel shell and the center electrode to insulate the center electrode when energized. 4. The lowest part of the steel shell is equipped with a curved side electrode. 5. The middle part of the steel shell has a copper gasket.
When it comes to replacing the spark plugs in a Focus, I’ve driven several models and based on experience, the general rule is to change them every 50,000 to 100,000 kilometers, depending on the engine type and driving habits. For example, the iridium spark plugs used in the 1.5L EcoBoost engine can last up to 100,000 km without issues. However, if you frequently encounter city traffic with constant stop-and-go driving, you might need to replace them earlier, say around every 40,000 km. The owner’s manual usually recommends this range. If you don’t replace them on time, weak ignition can lead to engine misfires, increased fuel consumption, and sluggish acceleration. Since buying the car, I’ve kept a maintenance log—don’t just focus on the spark plugs; also check the ignition coils and air-fuel ratio system. Otherwise, small issues can escalate into costly repairs. In daily driving, adopting a habit of gentle acceleration can slightly extend their lifespan—avoid stomping on the throttle. During regular maintenance, consulting your mechanic can save you a lot of hassle.
