For 2013, the Ram 2500 will also benefit from increased towing and GCWR. At 18,350 and 25,000, Ram 2500's towing and GCW ratings are also best among ¾-ton pickups.Ram Chassis Cab trucks also deliver maximum capability with best-in-class towing and GCWR figures 29,600 pounds and 37,500 pounds, respectively (5500 model). Ram Heavy Duty adds a number of new features for 2013, including a factory-integrated fifth-wheel and gooseneck hitch mount, a 17,000-pound Class V hitch with 1,800 pounds of tongue weight, class-exclusive electronic stability control (ESC) for dual-rear-wheels and a new Center High-Mounted Stop Light (CHMSL) –positioned camera, the first of its kind in the heavy-duty pickup category, to provide a full view of the bed for easier hook-up of fifth-wheel or gooseneck trailers as well as monitoring cargo. For 2013, all Ram Heavy Duty diesels benefit from an all-new cooling system. A high-efficiency fan, dual radiators, dual transmission coolers and low-slung charge air cooler afford 25 percent more heat-rejection capacity. Lower operating temperatures deliver improved performance, durability and lower operating costs. Cummins Turbo Diesel-equipped Ram trucks also provide best-in-class 15,000-mile oil change intervals. Ram is also introducing an industry-exclusive Ram Active Air intake system. When the intake system senses extreme heat, it draws cooler air from the front of the vehicle – a function that also engages at high altitudes for superior throttle response in low oxygen environments. When conditions are wet from snow, ice or water-fording, the system pulls air from an under-hood inlet, clear from snow packing and water. Also among the upgrades for 2013, Ram Heavy Duty front drive shafts and U-joints are sized larger to align with the truck's new Gross Vehicle Weight Rating (GVWR) and Gross Combination Weight Rating (GCWR). To handle the best-in-class towing capability of the new Ram Heavy Duty, a new front and rear suspension system with advanced geometry builds upon the chassis improvements and greatly improves overall roll stiffness. An advanced three-link front suspension on the Ram 3500 is necessary for the vehicle's higher GVWR and for use with heavy front loads, including snow plows. Additionally, a newly designed Hotchkiss leaf spring rear suspension on the Ram 3500 offers improved ride and handling while delivering higher towing and payload capability.