History of the Ford Super Duty, Part 3
Just two years after resetting the bar in the heavy-duty pickup segment, Ford was at it again in 2007. This time, the Dearborn-based truck maker was revamping its Super Duty for the ’08 model year. The chassis and suspension were reworked in order to accommodate a brand-new diesel engine, higher towing capacities and best-in-class payload ratings. For improved curb appeal and functionality, the face of the truck was redesigned, telescoping tow mirrors were added and the industry’s first integrated tailgate step debuted.
The biggest news was the Ford F-450, which boasted a 24,500-pound fifth-wheel tow rating and 33,000-pound GCWR, a maximum payload capacity higher than 3 tons and those signature 19.5-inch forged polished-aluminum wheels that made it look more like a semitruck than a pickup. Under the hood, which measured four inches higher than the outgoing ’07 model, the all-new 6.4L Power Stroke diesel could be optioned, and was by most buyers. For the first time, Ford’s diesel option featured quiet, clean-burning common-rail injection—and the 350hp V-8 also came with the segment’s first factory compound turbo arrangement.
6.4L Power Stroke
The 6.4L Power Stroke marked the last diesel engine Navistar International would supply Ford for use in its Super Duty’s, and you could say it went out with a bang. Not only was the 390ci V-8 equipped with a compact compound turbo system straight from the factory (Ford called it “series sequential”), but its Siemens-sourced high-pressure common-rail injection system employed quick-firing piezoelectric injectors, a first for the segment. As a result, the ‘08 Power Stroke was the quietest Power Stroke to ever grace a Ford truck, but also the most powerful, generating 350 hp at 3,000 rpm and 650 lb-ft of torque at 2,000 rpm.
Never Breaking A Sweat
Having been designed around what would be going into its F-550 trucks, the ’08 Super Duty’s cooling system erred on the side of extreme overkill. In fact, Ford widened the front boxed frame rails in order to accommodate its 33-percent larger radiator. Complementing the radiator was a larger engine-mounted fan shroud for improved airflow efficiency and a 140-gpm water pump (vs. 75-gpm on the 6.0L Power Stroke). Even a fuel cooler and power steering cooler were part of the ’08 Super Duty’s extensive list of heat exchangers.
DPF Added, 2007 Emission Standards Met
With more stringent particulate matter and NOx emission standards on the horizon, Ford and International had no other choice than to embrace the pollution-solving devices of the day: a diesel particulate filter (DPF) and exhaust gas recirculation (EGR). Use of the DPF helped reduce particulate matter output by more than 90-percent and, no doubt learning lessons from what the 6.0L Power Stroke had taught them, two EGR coolers were employed on the 6.4L Power Stroke. Additionally, a stronger DC motor was employed to open and close the EGR valve, making stuck EGR valves much less common.
A Tougher TorqShift
The 5R110W TorqShift remained for the ’08 model year, but (at least on diesel-mated models) received several upgrades. One improvement in particular was the five-speed automatic’s being treated to a 5-pinion overdrive planetary (vs. a 4-pinion version in the 5R110W behind the 6.0L). Ford also all but perfected its TowCommand system, which revolved around the factory-integrated electronic trailer brake controller, a fine-tuned braking strategy based on the truck’s ABS braking performance, the 5R110W’s Tow/Haul mode and Ford’s all-new telescoping sideview mirrors.
As for the sheet-metal, the cab, fenders and tailgate were all new for ’08. The grille was also enlarged for better airflow and mounted to the hood for the first time. Aside from the grille, the stacked headlight arrangement was arguably the most noticeable exterior change that occurred between the ’07 and ’08 models. The tow-friendly, telescoping sideview mirrors (which Ford called its PowerScope mirrors) could be extended outward nearly 3 inches at the touch of a button, and were also available with heated glass, integrated turn signals and clearance lamps. On select single rear wheel model trucks with four-wheel drive, 20-inch forged polished-aluminum wheels were an option, with the 19.5-inch 10-lug versions you see here being available on F-450 models.
A revised frame required modification of the rear sections in order to accommodate the truck’s 66-inch long leaf springs (8-inches longer than ’05-’07 models, from the center of the axle forward). The new rear leafs provided more windup stiffness and were key in achieving the truck’s higher payload capacity without sacrificing ride comfort. The thickest leaf packs were reserved for F-450 models, a truck that—when properly equipped—could carry 6,120 pounds on its back.
Class 4 Capability
While Ford’s F-250 and F-350 trucks were certainly nothing to scoff at, the F-450 did all the record-setting in ’08. It laid claim to best-in-class fifth wheel towing (24,500 pounds), conventional towing (16,000 pounds) and payload (6,120 pounds), as well as GCWR (33,000 pounds), GVWR (14,500 pounds) and front GAWR (6,500 pounds). By comparison, a properly optioned F-250 could tow 16,400 pounds via fifth-wheel, 12,500 pounds conventionally and haul 3,170 pounds in the bed. As for 4x2, DRW versions of the F-350, fifth-wheel maximum towing checked in at 18,700 pounds, conventional towing at 15,000 pounds and payload capacity topped out at 5,720 pounds.
The 10.5, Dana 80 and the S110
There were a trio of rear axles available in ’08: the familiar Ford 10.5-inch for all F-250 and single rear wheel F-350 models, the Dana 80 on dual rear wheel F-350’s, and the Dana S110 on the F-450. The latter axle came with a massive, 12.25-inch diameter ring gear (for comparison, the Dana 80’s is 1-inch smaller), full-floating 34-spline axle shafts, an 11,000-pound GAWR and could be had with either a 4.30:1 or a 4.88:1 ring and pinion. While a Dana 60 solid axle (complete with the carryover coil over suspension) could be found under the front end of all 4x4 F-250, F-350 and F-450 trucks, the F-450 got the Super 60 (which technically debuted on F-450/F-550’s in 2004).
More From Driving Line
- Missed out on the big changeover to front coil springs and radius arms? Take a trip back to Part 2 for the full scoop.