Bosch Double Iridium Spark Plugs feature both an iridium firing pin and an iridium ground electrode inlay that offer higher performance and 4X longer life compared to standard copper spark plugs 360-degree laser welded ultra-fine wire iridium firing pin provides better ignitability - reducing voltage requirements up to 24% - and enhanced durability Nickel-plated rolled threads provide superior resistance to corrosion and do not require anti-seize - making installation quick and easy Bosch Double Iridium spark plugs are pre-gapped at the factory and ready to install right out of the box - gap adjustment prior to installation not required Meets or exceeds manufacturer design requirements for OE fit, form, and function for modern gasoline engines - including Gasoline Direct Injection (GDI) engines Compatible with select vehicles (Note: engine affects fitment - verify specific fitment details with amazon confirmed fit fit checker above): BUICK: 1986-88 Century, 1986-87 Electra, 1986-88 LeSabre, 1986-87 Riviera, 1986-88 Skylark, 1986 Somerset Compatible with (continued): BUICK: 1985 Somerset Regal; CHEVROLET: 1998-03 Cavalier, 1997 LUV, 1995-03 S10; FORD: 1990-95 Aerostar, 1985-90 Bronco II, 1991-95 Explorer, 1982-83 F-100, 1983 LTD, 1979,1983 Mustang, 1985-92,2012 Ranger, 1984-94 Tempo Compatible with (continued): FORD: 1983 Thunderbird; GMC: 1995-03 Sonoma; ISUZU:1996-00 Hombre; MAZDA: 2001-10 B2300; MERCURY: 1983 Capri, 1983 Cougar, 1983 Marquis, 1984-94 Topaz; MERKUR: 1988-89 Scorpio; OLDSMOBILE: 1986-87 98 Compatible with (continued): OLDSMOBILE: 2001-02 Aurora, 1985-87 Calais, 1988 Cutlass Calais, 1986-88 Cutlass Ciera, 1987-88 Cutlass Cruiser, 1986-88 Delta 88, 1999-02 Intrigue, 1986-87 Toronado; PONTIAC: 1987-88 Bonneville, 1989 Firebird Compatible with (continued): PONTIAC: 1985-87 Grand Am, 1989-90 Grand Prix, 1998-02 Sunfire