There is always a large debate between smaller and larger ignition cables. Some end users believe that larger ignition cables can handle more voltage so they are suited better for high performance vehicles. However, this is completely false. Magnecor ignition wires range from 7mm think to 10mm thick and all provide the same amount of spark energy. The smaller ones are better for OEM applications while the larger ones are better for vehicles with an upgrade ignition system.
Large ignition wires use a thicker insulation jacket to handle the extreme temperatures associated with high performance vehicles. Vehicles that drive under normal conditions do not need anything more than an 8mm ignition cable because the temperatures do not get too hot. Smaller spark plug wires have a smaller insulation jacket that does just fine under normal conditions. However, if you use 7mm wires or 8mm Magnecor wires on a high performance race vehicle, they will eventually melt. Insulation jacket size does not relate to how much spark energy Magnecor ignition wires can handle.
Instead of being worried about cable size, you should be more concerned about selecting the proper conductor cables. Magnecor ignition cables come in solid conductor, carbon conductor and wound wire conductor along with the different sizes. The 10mm ignition cables made from wound wire is the best situation for high performance needs. On the other hand, a 7mm ignition cable with a carbon conductor is the best selection for OEM applications in which there is no ignition modifications.