This plug is one heat range colder than the factory plug on non-SVT Zetec equipped models. The SVT model uses a colder plug like this one from the factory due to its higher compression ratio but it is platinum instead of copper. This is a superior plug for mild nitrous or force inducted applications on non-SVT models. It can be used on SVT models but will support a lower amount of increase in power due to the SVT's 40hp advantage from the factory. For higher horsepower applications on Zetec engines, our Denso spark plugs will be a better choice.