Spark Plug resistance

[94_c/1500]

I wish I would of done this to new plugs, so the next set I buy I will post up the results.

Copper Resistors AC Delco CR43TS

I found the resistance on these plugs, which are used with about 5,000 miles, to be about 5.2 K - 5.8 K on the set of six I tested.

I got bored and measured the ground strap. I found them to be from .1131 to .1160 and that is from the same used set.

Platinum 41-803

I found the resistance on these plugs, which are used with about 10,000 miles, to be about 4.2 K - 6.2K on the set of six I tested.

The ground strap width was .1132 to .1159 and that is the same set as the resistance test. I couldn't measure one plug because some porcelain had found its way to the ground. The gap was nearlly closed with porcelain, which is why I will never buy these plugs again. I also had another with the same problem, but it wasn't as severe.

The copper resister plugs I have been told should have less resistance, but from my tests its about a tie. I only have 6 of each, so I need more to test. But the copper resistors were more consistent.

I had never realized the amount of resistance of a spark plug. So this leads me to beleive getting low resistance plug wires is a waste unless you are looking for every bit of power out there.

But this also leads me to beleive there is more on the table for those who are willing to buy more spark plugs in order to find the ones with the lowest resistance.

[94_c/1500]

And the tests were done with a Fluke 115 and a Mitutoyo 0-1 mic.

[xch3no2]

And what do we have when we put resistors in series?

Ahhh..

Just trying to complete the school,.. I mean circuit for ya!

The plugs resistance is so the tip doesn't "leak" voltage, rather blasts it out in one controlled burst then back to stopping it again.

Actual resistance seen by the coil is heavily affected by combustion mixture & pressure.

[Justin_Inc]

you must be really bored to think that this would make any difference at all.... basically you did a bunch of work for nothing.

[AuburnTruck93]

resistance also affects the time that it takes current to complete the circuit. in an auto application it is VERY small due to the limited distance but every little bit helps.