The distance from the coil pack to plug is a short run so you don't loose spark. A thicker wire offers less resistance so you get a better spark and this was more beneficial in the day when spark plug wires were longer, like in the 1977 Trans Am (yea I owned one). With our cars running individual coil packs per cylinder and short run wires you will not gain a greater spark where you will see any difference in horsepower. Did that help