By G.R. Whale
We know there's a lot of engineering that goes into a making a good 4x4 pickup truck, but for this Challenge we decided to focus on our two contenders' capabilities off the pavement, first looking at their "slow-go" talents and then at their "fast-go" off-road talents.
On paper, the 2015 Ram 1500 Rebel's impressive crawl ratio (1st gear multiplied by low range multiplied by axle gear) of 48.7:1 is impressive, but we don't drive on paper. While finessing our way up obstacles in 4-Low, we found the Rebel's throttle response demanded a delicate touch. It needed more restraint and sensitivity than the 2015 Toyota Tundra TRD Pro, which has a crawl ratio of 37.8:1. In fact, in certain situations when in low range, the Rebel got plenty of wheel speed but then upshifted a little early, bogged a bit, then downshifted again and repeated the cycle enough that it had one of our drivers thumb-shifting with the manual control on the steering wheel to get a smoother drive. In comparison, the Tundra's throttle response and gear-holding seemed more suited to the off-road fun we were having; it sauntered steadily in almost all climbing and sand-running situations.
During our steep downhill descents, we put both competitors in 4-Low and 1st gear and released the brake pedal to see what kind of "holding" power the transmission would create. Neither truck had a hill descent feature, so this is where we'd likely see how well the transmission's control module could predict what we needed. The Tundra slowly rolled up to 3,800 rpm, moving to an indicated 9 mph, and then leveled off on the steepest part of the long hill descent.
The Rebel, on the other hand, rolled up to 5,500 rpm on the same decline, moving at an indicated 10 mph, and continued to accelerate. Fearing an auto upshift, we applied the brakes to slow down. On our second attempt, we saw 5,800 rpms, so we braked again.
The Tundra made us feel more comfortable on steep descents, giving us more confidence. We can't say whether this is a result of the Tundra's engine construction, valve timing available from separate intake/exhaust cams, programming, torque converter or some combination thereof.
Crawling through deep, rutted trails, the Tundra seemed to offer better suspension articulation, especially when looking at rear-axle droop. We measured more than 16 inches from fender to tire during one flex, despite a calculated payload rating that is nearly 40 percent higher than the Rebel's. However, we found the Rebel had a good limited-slip differential (our tester had only 2,400 miles on the odometer), much smoother electronic traction control, and it was less prone to rear wheel hop than the Tundra.
On moderately slippery surfaces, the Tundra's tires with their more laterally oriented tread blocking had an easier time finding something to grab, while the Rebel required more momentum in situations where the axle could not droop enough to give the tire treads enough grip.
We should note the Rebel's as-delivered tire pressures of 55/45 pounds per square inch (front/rear) were considerably higher than Tundra's 33/33, so the Tundra's tires seemed to wrap around rocky obstacles better, but that didn't hurt the ride on hard pavement. With a load capacity nearing 3,200 pounds per tire, none of the treads required anywhere near maximum pressure.
With the Rebel's air suspension lifted to its tallest off-road setting, both trucks seemed to scrape and bang obstacles similarly, with the Tundra's front tow hooks and the Rebel's bumpers and center skid plate taking the brunt of the more significant hits. Surprisingly, we never dinged any tailpipes or ripped off mud flaps.
The Rebel's big advantage in this 4x4 slow-go contest is a 5-foot tighter turning circle; you can feel the front wheels beneath your feet when navigating a tight trail. The Tundra's front tires feel like they're quite a ways out in front of you. That meant more Tundra steering input (and effort), while the Rebel's electric assist felt a touch better than Toyota's hydraulic assist.
Cars.com photos by Evan Sears