Discover the high-performance BIOGAS ENGINES G3516/G3516E/G3516C spark plugs, designed for ERPILLAR 194-8518/301-6663/149-9931 applications. These durable spark plugs feature a double 'J' gap iridium electrode, resistor type, and flat seat for optimal performance in biogas engines. Perfect replacements for CHAMPION, BOSCH, and other leading brands.