What will happen if the car doesn't change the spark plug for a long time?

If the spark plug is not changed for a long time, it will cause: 1, and the fuel consumption will increase. 2. The car lacks power. 3. It's hard to start. 4. Engine jitter. 5. Increased carbon deposition. 6. Destruction of three-way catalysis. 7. Exhaust emission is not up to standard. Reasons for shortening the service life of spark plugs: 1. Fuel quality is not up to standard: I often go to some private places or places where the oil quality is not up to standard to refuel. 2. There is something wrong with the fuel quality: it will cause abnormal combustion. This is also the biggest reason that affects the service life of spark plugs. 3. Long-term overloading of cars: for example, cars are often full or even overloaded. There are also heavy goods that are often pulled. 4. Bad driving environment: for example, often running the construction site, driving in muddy sections, mountain roads and other places.