Since the total was 85 percent of GCWR, all towing was done in tow/haul mode and more than doubling the weight did the same for 0-to-60 times. The converter grabs around 1700 rpm but the 6.0 still feels bogged-we joked that a 3000-stall unit would help here. Once up to speed, the six-speed does a good job of choosing the right gear, and the extra midrange ratios quiet things noticeably as grades that put a four-speed at 4600 rpm were going by at closer to 3200 rpm. Tapping the brake pedal got the automatic into slowing mode, dropping gears for compression braking, and we used the thumbshifter for planning ahead on descents; almost every time we forgot we first had to shift the quadrant to "M" and then change gears with the thumb toggle.

In temperate weather of 65-75 degrees F, the water temperature indication was glued a needle above 210 regardless; the transmission digital display, which always had to be called up at restart because the park sensors were turned off, showed 180-185 degrees in steady cruising and went up to 228 F on the winding climb to 2500 feet. Consider the transmission cooling package (RPO KNP) not on our tester for warmer or more heavily loaded conditions.

The 2500 was quite comfortable dragging this load behind and felt a lot like an NHT Max Silverado. No endless bobbing and bounding, no loss of steering feel, no tail wagging, just point it and go. The 2500's steering gives up some precision and lock to the 1500's rack-and-pinion, though we never beat the pump maneuvering the 2500 as we did with the half-ton.

Go Figure (EIGHT)
We ran the figure-eight course at a constant speed for cornering, not transitions, and found the combo would round the cones in about the same speed as an average cute 'ute in the low 30-mph range (compared with the hi-po Infiniti FX50, which went through the course five to six mph faster). We surmise the tongue weight of the trailer was "pushing" the rear end, keeping the Sub better balanced than its nominal empty understeer attitude. Its tires scrubbing, the stability system kept quiet, and with the boat cleanly following the Sub, one observer noted that big 'utes handle like boats, but the boat handled better.

Most of this behavior continued on the open road, where we took freeway ramps at the same speed as mainstream traffic assuming we had the horsepower. On one particularly winding mountain road where we weren't pushing nearly as hard as around the F8 cones, the stability indicator tended to blink as the rear axle passed the apex, and while it didn't add any braking it kept us out of the throttle momentarily right when we wanted a full-throttle downshift. Using the defeat stopped such antics, and we stayed on the road just fine.

By volume and dimension the Expedition EL is the closest competitor, and with Sub 2500 sales about 10 percent of the 1500 there may be no need for an EL HD. The Expedition doesn't carry or tow as much as the 3/4-ton Sub but has the third-row advantage in room and folding and is down 52 horsepower but only 18 pound-feet, which comes on earlier. A 5.7-liter Sequoia outpowers them all and has the same GCWR as the Sub 2500; the Sequoia is lighter, so it can pull a bigger trailer, but it can't carry the same crew.

Unless you're in commercial delivery, where every pound of trailer weight counts, we think the Sub 2500 makes a better family or recreational tow vehicle than a maxxed-out half-ton. Although pricier at $53,415 as is, the Sub will handle up to a 7500-pound trailer just as well, have superior range, ride smoother, and coddle the occupants-across three rows rather than two-better than any crew cab.

Comparing Base 4WD Competition
  Suburban 2500 Ford Expedition EL
Base powertrain 352-hp/383-lb-ft 6.0L OHV V-8/6A 300-hp/365-lb-ft 5.4L SOHC V-8/6A
Optional powertrain None None
Suspension, f/r Indep coil spring/solid-axle leaf spring Indep coil spring/indep coil spring
Turning circle, ft 45.3 43.9
Std tire LT245/75R16 P265/70R17
Weight, lb 6328 6080
GVWR, lb 8600 7850
Cargo cap, cu ft 45.8/90.0/137.4 42.6/85.5/130.8
3rd row head/leg/shoulder room, in 38.1/34.9/64.7 38.0/37.7/67.1
Max advertised tow cap, lb 9400 8750
Wheelbase, in 130 131
Length/width/height, in 222.4/79.1/76.8 221.3/78.8/78.3
Fuel capacity, gal 39 33.5

Comparing Base 4WD Competition
  Nissan Armada Toyota Sequoia
Base powertrain 317-hp/385-lb-ft 5.6L DOHC V-8/5A 276-hp/314-lb-ft 4.7L DOHC V-8/5A
Optional powertrain None 381-hp/401-lb ft 5.7L DOHC V-8/6A
Suspension, f/r Indep coil spring/indep coil spring Indep coil spring/indep coil spring
Turning circle, ft 40.8 39
Std tire P265/70R18 P275/65R18
Weight, lb 5661 5920
GVWR, lb 7250 7300
Cargo cap, cu ft 20.0/56.7/97.1 18.9/66.6/120.8
3rd row head/leg/shoulder room, in 35.9/32.2/63.7 38.5/35.3/65.7
Max advertised tow cap, lb 9000 10,000
Wheelbase, in 123.2 122
Length/width/height, in 207.7/79.3/78.0 205.1/79.9/74.6
Fuel capacity, gal 28 26.4