DETROIT, May 6, 2011 /PRNewswire/ -- Every year, Jennifer Thompson, an equine veterinarian, takes her passion for horses on the road, leaving her native Wisconsin to compete in horse-and-carriage driving events throughout the eastern half of the United States. She relies on the trailering capability of her GMC Sierra HD.
"I really appreciate my truck's power when merging onto the interstate and towing over mountains," said Thompson, who uses a Sierra 2500HD with Duramax 6.6L turbo diesel V-8 to tow a 36-foot, gooseneck-hitch horse trailer. "I also appreciate the engine's ability to hold the trailer back when going downhill so that I don't need to ride the brakes."
Sierra HD's "smart" exhaust brakes are one of the advantages available on GMC heavy duty trucks, which offer a segment-leading fifth-wheel trailer weight rating of 21,700 pounds (single rear-wheel models only) and best-in-class weight carrying hitch capability. In addition, 2011 diesel-equipped Sierra HD's offer 11 percent better highway fuel economy than previous models and a larger 36-gallon fuel tank – both of which help to extend highway range to an estimated 680 miles.
"On one trip we were driving over the mountains of Pennsylvania, trailering three horses and 10-days' worth of feed, hay and luggage weighing a total 15,500 pounds, and the Sierra never even burped," Thompson said. "My fellow driver, who owns a Ford F-250, was really jealous."
The "smart" exhaust brake is standard on 2011 Duramax-equipped Sierra HDs. This driver-selectable feature uses the turbine control of the variable geometry turbocharger and the compression of the engine to generate backpressure, slowing the vehicle without applying the brakes. It is integrated with cruise control and varies the engine braking to account for grade and vehicle load. The exhaust brake also helps prolong brake life and prevents overheating the brakes on long, downhill grades.
Sierra HD's trailer sway control system provides an added measure of towing confidence. The system senses conditions of lateral movement and intervenes with braking and/or reduced engine power to bring the trailer under control and keep it on its intended path. The system uses electric trailer brakes when a trailer is plugged into the standard wiring harness of the truck. The driver doesn't have to do anything.
Sierra HD's hill start assist system also provides peace of mind by automatically engaging when sensors detect the vehicle is on a grade of about 5 percent or greater. It holds the brakes for about 1.5 seconds or until the gas pedal is pressed, preventing rollback. It is particularly effective when towing, giving the driver time to switch from the brake pedal to the gas pedal.
Sierra HD's available Rearview Camera System makes aligning the truck's hitch with the trailer easy by projecting images onto the rearview mirror display or onto the optional in-dash navigation screen. This also makes it easier to maneuver while backing into loading areas.
These and other safety features and functional technologies undergo extensive real-world testing before going into production.
"For towing capability we test our vehicles under maximum load conditions and under extreme conditions, like Death Valley when it's 120 degrees Fahrenheit, and up and down long, steep grades like Interstate 70 in Colorado up the Eisenhower Pass," said Jim Mikulec, lead development engineer for heavy duty trucks. "We go to extremes so that our customers can tow with confidence, even on snow and ice."
According to customer survey data, more than nine of 10 Sierra HD owners use their trucks to tow. While trailer weight rating is the top purchase consideration, vehicle comfort also ranks as a high priority.
"My truck has all the creature comforts a person could want in a vehicle. The seats are comfortable and the layout of the cab keeps everything you need within reach," said Tracy Bright of Ohio. The Sierra 3500HD owner competes in dressage, an arena event in which horse and rider execute a standardized series of movements. "There is no other vehicle I would consider for my trailering needs."
Bright relies on the 3500HD's Duramax turbo-diesel engine to haul her horses, Dusty El Nino and Diva Modena. The new 6.6L Duramax engine and other enhancements, including a new power steering pump, contribute to the truck interior's exceptional quietness.
"I love how quiet my truck is, and I hate pulling up next to a noisy other brand of diesel truck and not being able to hear myself think," Bright said. "I like to hear what is going on behind me. After all, my pride and joys are along for the ride."
GMC has built trucks since 1902, and is one of the industry's healthiest brands. Today GMC is evolving to offer more fuel-efficient trucks and crossovers, including the Terrain small SUV and Acadia crossover. The new GMC Sierra Heavy Duty pickups are the most capable and powerful trucks in the market. Innovation and engineering excellence are woven into all GMCs, including the Yukon and Yukon XL and full line of Sierra pickups. Today, GMC is the only manufacturer offering three full-size hybrid trucks. Details on all GMC models are available at www.gmc.com, on Twitter at @thisisgmc or at www.facebook.com/gmc.
SOURCE General Motors