The spark plug gap for a 2004 1.8t VW Passat Wagon is .032 in. (0.8 mm). This is the distance between the center electrode and the ground electrode of the spark plug. The gap is critical for proper ignition of the air/fuel mixture in the engine. If the gap is too wide, the spark will be too weak to ignite the mixture. If the gap is too narrow, the spark will be too strong and will damage the spark plug.
