Spark plug resistance R5 vs R6

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Ndx

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Hi guys,

Just bought new sparkplugs same part number but one set is R5 one R6

Little shocked that same part number but with different resistance.
 
Resistance only affects the spectrum output. If you don't have interference problems it won't make a diff.
 
Meaningless. With 30kv firing voltage, that resistance difference will not make any differences.
 
I doubt it's the resistance spec. Resistance is usually 5k ohm. 5k ohm vs 6k ohm makes no difference. Resistance is only to prevent the spark plug from acting like a radio-frequency transmitter antenna.

Is this an NGK plugs? 4, 5, 6, etc. would be the heat-conductivity spec, which makes a huge difference. Using the wrong heat conductivity will cause preignition (too little heat conductivity, spark plug running too hot) or spark-plug fouling (too much heat conductivity, spark plug running too cold).
 
Thx guys

FGR5NQE04 it's a Bosch Sparkplug for Porsche. / OE
 
Originally Posted By: KingCake
Resistance only affects the spectrum output. If you don't have interference problems it won't make a diff.


Exactly.

When you are firing in the 10k+ volt range, the resistance doesn't make too much of a performance or fuel economy difference for that resistance. What makes the difference on is the inductance (of the coil) and the resistance (from the plug) makes a low pass filter that filter out the noise so it wouldn't cause interference.
 
5 is the heat-conductivity spec, not the resistance. Make sure that you use the spark plug with the correct heat-conductivity spec as I explained above. They also have different part numbers; so, they gave you the wrong box.

Larger image: https://www.sparkplugs.com/Data/uploads/Charts/Bosch_Numbering_System.jpg

Bosch_Numbering_System.jpg
 
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