Which maintenance task is crucial for ensuring easy engine starting?

Maintaining spark plugs is essential for ensuring easy engine starting because they play a critical role in the ignition process. Spark plugs create the spark that ignites the air-fuel mixture in the engine's combustion chamber. If the spark plugs are worn, dirty, or damaged, they may not produce a sufficient spark, leading to hard starting or even engine misfires. Regular maintenance of spark plugs includes inspecting them for wear and replacing them as needed, which directly affects the engine's ability to start smoothly.

In contrast, changing the fuel filter is also important for fuel delivery, but it does not directly influence the ignition process as much as the spark plugs do. Checking tire pressure, while vital for overall vehicle safety and performance, does not affect engine starting. Inspecting the exhaust system is necessary for emissions control and overall engine efficiency, but it does not play a direct role in the ignition of the engine. Therefore, the maintenance of spark plugs is the most crucial task for ensuring easy engine starting.