Offroad Obstacle Course
Similar to our hill-climb testing, we had a choice with our offroad test: run it in on a real-world trail or in a controlled setting. We opted for the offroad obstacle course at GM’s Milford Proving Grounds. The obstacle course had a quicksand-like gravel trap, a steep 75-foot-long, 46.6 percent dirt mound (a gain of 46.6 feet in elevation for every 100 feet traveled), and two telephone poles buried horizontally at progressive heights.
Each truck was driven over the course at least three times. The trucks entered the gravel pit first, in high-range four-wheel drive, where they came to a complete stop to settle down into the loose rocks. Next, the driver accelerated out of the gravel to observe how well the trucks escaped the sticky pit. After the gravel, the trucks used 4-High to climb up the back side of the steep hill to assess power and traction. Then, it was over the pointed apex of the hill to gauge the breakover angle, then down the front side in 4-Low to assess the crawl ratio and hill-descent capabilities without brakes. Last, the trucks climbed over the two buried logs to assess obstacle clearance and fine control.
All the observations in this test were subjective.
The GMC Sierra All Terrain was the first truck driven through the course. It drove through the gravel pit with minimal hop and fuss, then up the steep grade with plenty of power from its 6.2-liter V-8. We had difficulty, though, getting low-range four-wheel drive to engage. It took a few minutes of fussing in neutral and driving the truck a few feet backward and forward before 4-Low locked. The crawl down the hill allowed for adequate control. The Sierra was able to clear both buried poles without striking the frame, rocker panels or front air dam.
The Chevrolet Silverado performed similarly to the Sierra, but with a few key differences. It was quieter through all the obstacles, and it scraped a bit at the top of the hill and, on some runs, over the second log.
Compared to the GM pickups, the Tundra bounced more coming out of the gravel pit – not a negative if you have to rock the truck out of a sticky spot. Power was excellent climbing the hill, but the Tundra’s shallow breakover angle caused it to scrape going over the top. The crawl down the other side didn’t require brakes. We cleared the first log but scraped up the running boards and frame going over the second pole.
The Dodge Ram started the trail by climbing smoothly out of the gravel pit, but when we started to tackle the 46.6 percent grade the engine stalled mysteriously. We weren’t able to repeat the stall with the Ram, nor did it happen with any of the other trucks. The Ram climbed the hill with good power and cleared the top without scraping. It had the lowest numerical crawl ratio of the tested trucks, and it whined the loudest as it descended the front part of the grade. The Ram climbed over both poles without scraping.
The Titan was the best all-around truck through the offroad course. It required the least amount of orientation for the driver to operate the switchgear, which was placed intuitively next to the shifter. It was the easiest truck to get out of the gravel trap, and it made short work of both sides of the hill. It’s high ground clearance also made walking the truck over both buried poles an easy effort.
The F-150 performed similarly to the Silverado. It had little difficulty getting out of the gravel pit, and climbing the hill only required a bit of extra throttle. There was scraping at the top of the mound that was repeated again over the second buried pole. The truck touched both points with the low third cross-member of its frame that hangs just below the bottom of the frame rails. The F-150 had the lowest and best-managed crawl down the steep side of the hill.