Spark Plug Wire Sizes

[theone]

does it really matter what size, i mean
i took my old but new wires off my car sense its down and put it on my other car, they were stock size.
so i have to buy me a new set....again. but i was wonder should i go bigger like 8mm, would this help with the ignition upgrade and other perfromance upgrades i have? Thanks
Theo-

[Kabuki]

Yeah, "better" wires don't add anything to the performance, or power, but worn wires or just poor quality wires can certainly cause problems.

[theone]

ok, thanks guys.

[HondaFan81]

NGK also sells 7 mm wires, I've been told 7 mm is fine for our 4 cyl engines....8mm won't hurt, but not necessary

[Andrew]

I've actually seen dyno charts where in aftermarket wires actually hurt performance (no, not Honda sponsored). Aftermarket wires are typically manufactured cheaply, which shows when the engine is near redline in misfires, which can kill a horse or two. In the testing, old Honda stock wires outperformed all comers.
Long and short - it's possible that if you build up an extremely powerful aftermarket inginition system that you'd need thicker wires to carry the spark, but right now you should be fine... and if you had built up such a system you'd probably be beyond most of our advice, anyways