Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance Plug wire measurements

High all, my name is Ashley and I'm new to the board. Been lurking a while, before my (2000, Black, SVT) purchase. Anywho, I decided to change plugs and wires, so I picked up a set of Autolite Plugs and Pro set of wires from Advanced Auto, thinking that the wires were spiral cores as the box would have you believe. I took a resistance reading of the longest wire and it was approx 20k ohms. Definitely not in the spiral core resistance range (MSD Super Conductors are listed as 40/50 ohms per foot). I'll be returning these and maybe trying the Bosch, which I believe are true spiral core design.

P.S. Don't have the extra dough for the Magnecores

As a word of warning, I just threw out a set of Bosch wires after about 25k miles of use. The wires started causing hesitation/bogging at upper rpms and a very slight misfire. Replacing with OEM Motorcraft wires (a used set at that) fixed the problem.

The "resistance of a wire" thinking most people use is extremely flawed and very out dated. It's from an era when the plug wires were nothing much more then thinly cased copper strands. When the strands broke the resistance shot up and the wire needed to be changed.


The entire "testing resistance" means absolutely NOTHING in the grand scheme of wires. Testing a wire with a miniscule voltage test (common Multimeter) does nothing but test continuity. While in use the 45000-60000 volts travel down the wire in a field and not in the central wire core. Therefore a wire's resistance to a 6-9 volt MM pashing through the core is meaningless for comparison.

It's nothing more the a marketing technique to make you think you bought this outstanding wire when in reality it means nothing at all.

Actually to achieve the lowering ohm's rating for marketing they use lower grade and thicker wire. This hurts the wire's ability to flow current. So normally a lower resistance rating means less current under real use.

Also to reduce EMI they use thick coatings that hamper the field and again lower the current.


So marketing and comparing wires by ohms rating is by far NOT the right way to go about things.