When a new generation of the GMC Sierra fullsize pickup heads into production, it will have already absorbed hundreds of thousands of miles of hauling, towing, use and abuse testing. It’s the kind of durability exam customers in the real world administer for years and even decades.
GMC vehicles are tested based on where and how our trucks are used to assure consumer demands are met - high in the mountains, low in the deserts, colder than -50 degrees in Canada and up past 120 degrees in Arizona.
Tammie Roeber, Dave Cleveland and Don Impson are three of those customers. Together, their trucks represent more than 2 million miles and two-and-a-half decades of proven GMC engineering.
“I signed the papers on my new Sierra 3500HD one-ton pickup in 2006, hitched up a trailer, and have been on the road since,” said Roeber, who has recorded more than 1.2 million miles on the original Duramax diesel engine and Allison transmission in her GMC. Roeber makes a living transporting horses across the eastern United States. “From 30 below zero in Minnesota to 100 degrees in Miami,” she said.
“I had two Ford pickups prior to owning my GMC, but I was replacing a transmission every year. If that rate continued, I’d be through my sixth transmission with the miles I’ve put on the Sierra. Most of Roeber’s miles have been driven pulling trailers, including a 48-foot, 16,000-pound trailer holding as many as nine horses. She maintains her truck religiously, sticking to a 15,000-mile oil change schedule. At her pace, that’s just three weeks between service visits.
Among Roeber’s favorite features are the truck’s engine braking capability – she often encounters 6 percent to 7 percent grades that stretch for miles – that’s allowed her four-wheel disc brakes to last longer, as well as the comfortable crew cab. With most of her life lived on the road, the rear seat often doubles as a bed.
Dave Cleveland uses his 2002 Sierra 1500 extended cab to travel from his home near Chicago to trade shows as far away as Florida and Colorado. Between those travels and his daily 60-mile commute, he’s accumulated 420,000 miles over the past decade. The truck shares a driveway with his wife’s 2010 Sierra.
“This truck runs as good today as the day I bought it,” Cleveland said. “The engine and transmission are original. I haven’t even replaced the brake rotors or shocks. Other than a rear pinion gear replacement and regular oil changes, it’s just had one major tune-up at 200,000 miles.”
Don Impson, a semi-retired veterinarian in Arkansas, has stretched his miles out longer than the others. He started accumulating his 520,000 miles – mostly by making farm visits tending to animals in a three-county area around his home – when he bought his GMC pickup new in 1986.
“Everyone down around us owns trucks, but no one ever talks about this sort of mileage on one engine,” Impson said. In addition to the original engine, his manual transmission still has its original clutch. “I bought a red and white two-tone truck off the lot because the colors were done wrong for a local construction company, but it’s actually become somewhat of a calling card. Everyone knows my truck.”
“In 1995, I bought another GMC ¾-ton pickup truck thinking mine may quit on me,” he continued. “Man, how wrong I was. The 1995 truck has mostly sat while my ’86 continues to get the work done. We’re both getting older, but me and the truck may still be hankering to make a cross-country trip and I bet we could make it.”
Customers like these help GMC make advancements in durability by providing real-world test results.
“Customer stories are great to listen to, and they provide useful data for planning new trucks,” said Jim Mikulec, lead development engineer for Sierra Heavy Duty pickups. “We test our vehicles based on where and how our trucks are used to assure consumer demands are met. Vehicle testing takes us high in the mountains, low in the deserts, colder than -50 degrees in Canada and up past 120 degrees in Arizona. These stories show that our diligence is paying off.”