GMCis the dedicated truck division of General Motors. However, it's fairly common knowledge that its vehicles are platform twins to various Chevys, typically differing mainly in styling and sharing the same strengths and weaknesses. For the 2014 GMC Sierra 2500HD, that's a good thing, as it means that there are plenty of plusses and not many minuses.Related to the Chevy Silverado 2500HD, the Sierra 2500HD neatly splits the difference between the 1500 light-duty pickup and the 3500HD ultra-heavy-duty workhorse (which can be had in a dual-rear-wheel configuration). Those considering the Sierra 2500HD have plenty of variety as far as powertrains and options go. Whether you want a basic, utilitarian work truck or a plush, six-passenger tow vehicle for your luxury RV or horse trailer, there's a rig for your needs here. Indeed, with a maximum towing capacity approaching 18,000 pounds, this Sierra should be able to handle most tasks with ease.One other interesting aspect about the Sierra 2500HD is its option to use either traditional gasoline or compressed natural gas (CNG) to power its 6.0-liter V8 engine. Given America's increasing natural gas production, this engine option is perhaps even more compelling this year. But this flexibility comes at a cost beyond the considerable price of this option. That's because the natural gas tank is mounted in the bed, using up about as much space as a large cross-bed tool box and thus reducing payload capacity.