Seafire XV
CEG'er
I have a stock 2.5 Duratec and I was wondering if there would be any problems if I were to use a set of Motorcraft plugs that are one step hotter. I don't have the part number with me at the moment, but I got a set a few years ago due to an ordering mixup by the supplier, who didn't charge me for them. I would hate to waste them, so what are the pros and cons? My engine runs fine with the stock heat range.