Though the 2014 Chevrolet Silverado and GMC Sierra 1500 sport the Gen V EcoTec3 line of efficient V-6 and V-8 engines, GM has just announced that the standard powertrain choice in the upcoming Silverado and Sierra 2500HD will be a Gen IV-based 6.0L V-8 that runs on gasoline, E85, and Compressed Natural Gas (CNG).
GM first began dabbling with CNG on a Gen IV with the 2012 Chevrolet Express van and commercial applications, creating the 6.0L LC8. Special hardened valves and valve seats allow the CNG compatibility, which is rated at 360 horsepower and 380 lb-ft of torque using regular unleaded gasoline (301/333 using CNG). The LC8 uses variable valve timing, a cast iron block, L92-style heads, and a 9.6:1 compression to generate its peak power at only 5400rpm (5000rpm with CNG) just like its L96 predecessor. The torquey 364cid motor will pull up to 14,700-pounds when paired with the beefy 6L90E trans, also in part due to a new 4.10 standard axle that increased the tow rating by 4,500-lbs.
For those of you wondering, the Duramax 6.6L turbo diesel V-8 is also available on the 2500HD and 3500HD, rated at 397hp and 765 lb-ft of torque, which is compatible with B20 biodiesel and mated to an Allison 1000 six-speed automatic transmission. On the 2WD 2500HD, the Duramax is capable of pulling 17,800-pounds, however, the 3500HD can manage a whopping 23,100-pounds with dual rear wheels and the regular cab, long bed. The 3500HD still uses the L96 Vortec V-8 is its standard engine, however, which runs on regular gasoline only.