2015 Dodge Dart 2.4 SXT
Copper plugs provide no benefit over iridium plugs in dodge darts. All spark plugs have copper cores, you're paying for the electrode tip metal. Copper plugs have a copper core with nickel tip and iridium plugs have a copper core with an iridium tip. Both of which doesn't matter as both have internal 5k ohm ceramic resistors (to limit RFI and damage from capacitance after-fire). Copper-nickel plugs are 2x less conductive than iridium, 2x softer, foul easier, and fire less consistently. They aren't even cheaper, at half the price, but need to be replaced 10x for every one set of iridium plugs.