champion iridium- boxed – rer8zwycb4 champion iridium – the ultimate element. This spark plug’s fine-wire iridium center and platinum ground electrodes provide the sharpest spark focus for maximum performance. heat-active alloy allows electrodes to reach optimal temperature quickly maintains stable operating temperature under all engine loads v-trimmed ground electrode promotes sharper spark focus fine-wire center electrode and v-trimmed for greater ignitability iridium center electrode delivers maximum life champion iridium – maximum performance. Premium spark plug champion iridium 9407 spark plug (carton of 4) application summary: acura lt. Trk.: 3.5l v6 (15-13), 3.7l v6 (13-10); acura pass. Car: 2.0l l4 (15-13), 2.4l l4 (14-09), 3.5l v6 (14-09), 3.7l v6 (14-09); audi lt. Trk.: 3.6l v6 (10-07); chrysler pass. Car: 3.6l v6 (14-11); chrysler van: 3.6l v6 (14-11); dodge lt. Trk.: 3.6l