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Here are the spark plug choices for the 997. The second one is the

factory spec. spark plug. Is one hotter then the other and which one

will make your car go fast when it is 90 degrees farenheit outside?

6 ea 999 170 207 91 Spark Plugs (Beru 14FGR 6KQU) MY99-MY01


6 ea 999 170 223 90 Spark Plugs (Beru FGR 5KQE0) MY02-


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Spark plug heat ranges are not directly related to making your car faster or slower. Use the coldest plug that allows complete combustion, easy starting and normal operating temperatures. Too hot of a spark plug can and will damage your motor. Too cold will cause poor performance, misfiring, etc.

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Hi Nick,

Thank you for the information. I am sure that

the 6KQ plug and the 5KQ plug are very close to each other.

Just like to know what other people would put

in their car.


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Use the colder plug. Generally a hotter one is for an engine with a lot of miles that may have ring sealing issues, bad valve guide seals or worn valve guides. Or anything else that would contribute to lower than normal compression or oil entering the combustion chamber requiring a hotter spark to start the burn.

High performance tuning, ie cams with more aggressive profiles, higher compression, bigger valves, supercharging, etc will usually call for colder than stock plugs because elevated running temperatures coupled with higher compression make the fuel easier to ignite.

Hope this helps.

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