Cat | Cat ® 3612 Industrial Diesel Engine | Caterpillar For your largest power needs in any environment, Cat ® 3612 Industrial Diesel Engines offer the unsurpassed performance and durability your customers need to keep their industrial applications and operations running. They deliver high power output, proven reliability and excellent fuel efficiency. These engines maintain low operating costs to keep your customers profitable for years to come. Cat | G3612 Gas Compression Engine | Caterpillar GERP is a PC-based program designed to provide site performance capabilities for Cat® natural gas engines for the gas compression industry. GERP provides engine data for your site's altitude, ambient temperature, fuel, engine coolant heat rejection, performance data, installation drawings, spec sheets, and pump curves.