Best Spark Plug Wires - PCM safe, Performance, Affordable
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Best Spark Plug Wires - PCM safe, Performance, Affordable
I'm working on putting together a replacement set of spark plug wires as I still have the originals and wanting to get some input. I'm pretty impressed at over 200k miles and 25 years the originals still fire at all. They all measure at ~4500 ohms/ft which is on the better end of FSM spec [3000-12,000ohms/ft].
I am replacing them even though they still work fine, for reasons of reliability and performance [including mpg]. I recently bought a set of FAST [previously CRANE] Firewire cut to fit plug wires on Amazon for a killer deal [$28 although I had to add a $15 set of straight boots because its all 90's]. They claim 25ohms/ft and measure around 40 which is close enough for me. They also claim to be very good for preventing RFI/EMI noise to radio and electronics stating "Perfect for EFI - FAST Firewire is the best spark plug wire on the market for fuel injection. The reactive core design effectively filters electro-magnetic interference and noise, which can wreak havoc on EFI systems."
After I purchased them I read somewhere that low resistance spark plug wires can permanently damage PCM's and other electronics. I knew about the radio interference which I was fine with but I'm not ok with damaging my PCM/ECU. So I wanted to ask what yall's thoughts are. Should I go with something else? My truck is not a race vehicle it's a beloved daily driver and I plan to keep it that way for many years, but I also want to do what I can to improve the performance including gas mileage so I don't want to just get cheapo parts store wires if I can upgrade for a reasonable price [under $120]. I read another thread on here recommending the Magnecors. Well those are ~ $360 which is way over my current budget and have a resistance around 2500/ft which is not much of an improvement over factory. I like that they claim to last far longer than others and it sounds like their RFI/EMI suppression is better but is it really? Obviously every brand is going to say theirs is the best or has this or that feature, who to believe? They [Magnecor] say all the other brands are junk or that you don't need low resistance to get best performance. I don't know. I also find it more complicated to try to find the Magnecors, especially if buying by the foot or a cut to length discounted kit. I want the best plug wires I can get [longlasting, better than OEM performance, safe for PCM/ECU] at a reasonable cost and I am willing to put them together myself to save money. I can get Taylor Spiro Pro 8mm wires for $2/ft which have 350ohms/ft and claim "Superior RFI / EMI suppression for applications with CD or electronic ignitions, on board computers, stereos or pit radios". That would be a reasonable price.
Could it be that over the past 2 decades the other name brands such as MSD, Taylor and FAST have upped their game as far as quality, RFI/EMI etc? Some claim MSD is junk and some claim it's the most durable/best. Does it matter how low the resistance is if the RFI/EMI suppression is strong enough? I also take as a factor the spark plugs have between 4k-10k ohms as well. Does anyone know if there is a minumum total resistance between the plugs and wires added up to prevent PCM damage? Has anyone actually damaged their PCM or other electronics from low res plug wires? I haven't heard any stories of this only warnings that it might.
These FAST plug wires apparently used to be CRANE Cams plug wires which had the same resistance, claim spiral core with kevlar so maybe these are pretty good. I'd love to stick with these but I don't wanna risk burning up my PCM. I suppose I could try them and turn on my radio and see if there's some noticeable interference from the new plug wires.
Give me your thoughts and thank you for your input!
I am replacing them even though they still work fine, for reasons of reliability and performance [including mpg]. I recently bought a set of FAST [previously CRANE] Firewire cut to fit plug wires on Amazon for a killer deal [$28 although I had to add a $15 set of straight boots because its all 90's]. They claim 25ohms/ft and measure around 40 which is close enough for me. They also claim to be very good for preventing RFI/EMI noise to radio and electronics stating "Perfect for EFI - FAST Firewire is the best spark plug wire on the market for fuel injection. The reactive core design effectively filters electro-magnetic interference and noise, which can wreak havoc on EFI systems."
After I purchased them I read somewhere that low resistance spark plug wires can permanently damage PCM's and other electronics. I knew about the radio interference which I was fine with but I'm not ok with damaging my PCM/ECU. So I wanted to ask what yall's thoughts are. Should I go with something else? My truck is not a race vehicle it's a beloved daily driver and I plan to keep it that way for many years, but I also want to do what I can to improve the performance including gas mileage so I don't want to just get cheapo parts store wires if I can upgrade for a reasonable price [under $120]. I read another thread on here recommending the Magnecors. Well those are ~ $360 which is way over my current budget and have a resistance around 2500/ft which is not much of an improvement over factory. I like that they claim to last far longer than others and it sounds like their RFI/EMI suppression is better but is it really? Obviously every brand is going to say theirs is the best or has this or that feature, who to believe? They [Magnecor] say all the other brands are junk or that you don't need low resistance to get best performance. I don't know. I also find it more complicated to try to find the Magnecors, especially if buying by the foot or a cut to length discounted kit. I want the best plug wires I can get [longlasting, better than OEM performance, safe for PCM/ECU] at a reasonable cost and I am willing to put them together myself to save money. I can get Taylor Spiro Pro 8mm wires for $2/ft which have 350ohms/ft and claim "Superior RFI / EMI suppression for applications with CD or electronic ignitions, on board computers, stereos or pit radios". That would be a reasonable price.
Could it be that over the past 2 decades the other name brands such as MSD, Taylor and FAST have upped their game as far as quality, RFI/EMI etc? Some claim MSD is junk and some claim it's the most durable/best. Does it matter how low the resistance is if the RFI/EMI suppression is strong enough? I also take as a factor the spark plugs have between 4k-10k ohms as well. Does anyone know if there is a minumum total resistance between the plugs and wires added up to prevent PCM damage? Has anyone actually damaged their PCM or other electronics from low res plug wires? I haven't heard any stories of this only warnings that it might.
These FAST plug wires apparently used to be CRANE Cams plug wires which had the same resistance, claim spiral core with kevlar so maybe these are pretty good. I'd love to stick with these but I don't wanna risk burning up my PCM. I suppose I could try them and turn on my radio and see if there's some noticeable interference from the new plug wires.
Give me your thoughts and thank you for your input!
Last edited by DF-WKT; Apr 29, 2026 at 03:09 PM. Reason: typo
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From: Clayton MI
I suspect the 'electronics damage' comes from the magnetic fields produced by the wires when they are passing current..... Low resistance means stronger fields. That said, if the company claims they are good for fuel injection, what it comes down to is: Do you believe them? Maybe check reviews, and see if anyone has anything to say about them?