When the bore and shaft centers are misaligned, seal life will be shortened because the wear will be concentrated on one side of the sealing lip.
Furthermore, iridium spark plugs are designed to withstand high temperatures and extreme conditions inside the engine. This means they are less prone to fouling and misfiring, even under intense driving conditions. This reliability makes iridium spark plugs a great choice for performance cars or vehicles that are used for towing or heavy-duty applications.