I was wondering what the difference in temperature ranges for spark plugs does? My plugs are all fouled because im running crazy rich. I had some local guys take a look at my car that know more than i do about tuning with plugs etc, and they suggested a plug 2 colder than stock. What would the part # be for this? Any help is appreciated in the explanation or part #

 

The numbers differ according to plug manufacturers.

There is more ceramic on the plugs to absorb more heat. In NGK, you can usually buy 7's off the shelf. They have higher, but I believe you have to special order them.

The colder the plug, the crappier the idle.

 

if your stock plugs are being fouled, a colder plug will foul up even quicker. Unless you get your fuel tuning problem corrected don't bother going to a cooler plug. For daily driving I would suggest one step colder at the most, heat range 7 in an NGK plug would work well. Two steps colder would be more of a race setup where you really need a cooler plug, and where using very high compression, but for street driving you need the plug to be warm enough to burn off deposits. But you should still get that fuel tuning corrected.

Joey

 

well my compression is 12.5:1 should i still go with a stock plug? I probably wont get my car tuned for a while