Ignition cables info please

[AriK]

When i bought my car 6 years ago i began cleaning up my engine compartment, aesthetic-wise. One of the items i replaced was a set of spark plug wires. I installed a set of Accel 8.8 mm, mostly because of their vibrant appearance. Never had an issue ever since.
A new to me mechanic did some work on my car today and made an observation that these wires create TOO MUCH resistance and i should look into getting myself some normal thickness 7mm NGK s. He said that while 8.8 s may perform well on a Chevy 350, they do not do me any favors on a 2 liter Fiat. According to his timing light they are firing below potential and it's because of their increased thickness. The engine runs like clockwork, absolutely no hiccups.
I was always under the impression that the thicker the wire, the less resistance. Does anybody have any input on ignition cables and Fiats! Does Marelli favor an appetite for specific brand cables? The cables have 10 000 miles on them over a period of 6 years. When i get the car back i'll take some readings on those wires, what numbers should i expect

[aj81spider]

I am not qualified to comment on better or worse wires, but you are correct that the thicker the wire the lower the resistance.

[So Cal Mark]

find a new "mechanic", keep the wires

[TX82FIAT]

I run Accel 8.8 on my car because of the ability to cut to custom length. No issues, thicker is less resistance. However, think of current in terms of water flow. You have a wider pipe so you need a good spark. I really don't think such a small difference makes any difference. The car runs and has run well for some time.

[rebar1111]

Thicker is better.

If the spark is weak, check the coil.

[chrisfiat]

the 8 mm dimension of those wires is NOT the actual size of the current carrying internal element, which is most likely a carbon thread, but is the outside diameter of the insulation of the wire. It's purpose is to offer higher insulation properties to prevent spark leakage. so if they work for you then use them, also a certain amount of resistance is necessary in the ignition system to encourage spark build up with out it you would have very low spark energy.

[So Cal Mark]

resistance in the wires is a direct result of the length of the wire and the material in the strand carrying the current. Resistance in the wire is not needed to produce spark. You could use a coat hanger between the coil and spark plug, although without insulation you'd have lots of arcing

[majicwrench]

I'm with Mark, find a real mechanic. The difference in plug wire thickness is in the insulation, not the core. Your fiat is using the same basic igniton technology as a chev 350. The guy is a flake.

[chrisfiat]

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