by JEFF JOHNSTON
Ford has introduced its new Triton V-10 gasoline-powered engine, the first 10-cylinder power plant available in a Class C cutaway motorhome chassis. The manufacturer claims the new engine will give motorhome owners upgraded performance in the form of increased fuel economy and improved acceleration, hill-climbing and towing ability.
As a direct replacement engine for the venerable
7.5-liter (460-cid) V-8, the 6.8-liter Triton V-10 is part of Ford's new modular family of
light-truck and automobile power plants. The V-10 is first available in E-Super Duty
motorhome chassis and Econoline vans; we expect it will be available in Class A chassis
soon. The engine is rated to produce 265 hp at 4,250 rpm and 405 lb-ft of torque at 2,750
rpm, as compared to 245 hp and 400 lb-ft at 2,200 rpm for the 7.5-liter V-8 in RV chassis
applications. Multi-point fuel injection regulated by Ford's fifth-generation Electronic
Engine Control (EEC-V) system provides efficient, clean-burning use of the fuel.Although it displaces 6.8 liters, somewhat smaller than the old 7.5-liter V-8, an efficient new design that includes overhead cams, a serpentine accessory drive belt and other state-of-the-art features give the engine the guts to do the job. Ford developed a V-10 instead of a new, larger V-8 because it allowed the company to make use of many existing Triton V-8 components, thus, the "modular" engine concept. The V-10 shares 58 percent of its parts with the V-8 engines in the Triton family.
A fail-safe cooling system is part of each Triton V-10. In the event of a cooling-system failure, the engine runs on alternating sets of cylinders to allow one set to cool off before switching back to it. If the temperature reaches a critical level, the engine shuts down to prevent costly damage.
A new instrument panel with redesigned controls, a new bumper and grille, a new engine cover and stronger floor assembly are among the other changes made to the E-Super Duty chassis for '97.
During a recent Ford media event to introduce the V-10, we had an opportunity to take a 270-mile test drive through the country around Nashville, Tennessee, behind the wheel of a Fleetwood Tioga Class C powered by the V-10 engine and fitted with a 4.63:1 axle ratio. The motorhome weighed 12,470 pounds with full fuel, but no water or propane aboard, and the chassis was rated 14,050 pounds gross vehicle weight rating (gvwr). One feature of the V-10 that stands out is its quiet, smooth-running performance. The engine vibration and noise transmitted to the driver's area are minimal, coming through as no more than a low murmur. Kicked in the pants with the pedal to the floor, the Triton V-10 simply purrs a bit louder than normal. A Ford engineering spokesman explained that the V-10 has sequential cylinder ignition, a feature that helps smooth its operation. A balance shaft in the left cylinder head likewise aids in damping vibrations. The chassis' sound-deadening insulation package has been improved to further quiet the passenger compartment. Although quieter than its 7.5-liter predecessor, the V-10 still rumbles enough to let the driver know a powerful engine is at work.
Like the other Triton engines, the V-10 is a high-revving son of a gun. It incorporates a fuel-cutoff device that engages at 5,150 rpm in first or second gear, and 4,800 rpm in third or overdrive gear. This device slowly reduces the fuel to the engine, which in effect prevents the operator from over-revving it during hard acceleration or hill climbs.
We topped a 5 percent grade at 53 mph in third gear, with some throttle to spare, and a 6 percent hill slowed us to 48 mph in second gear, once again with some extra gas-pedal travel left over. In both examples, the road was too curvy and the traffic was too busy to drive any faster with safety. Due to the nature of the roads, we didn't start up these hills at 55 mph or better highway speeds. Each was approached at about 45 mph, and our top speeds were recorded after accelerating up the hills.
Throughout the drive, the engine felt as though it was easily, if not effortlessly, packing the coach down the road. Some motorhome engines always appear to be working hard to maintain headway, but the V-10 made short work of the task and seemed to be loafing along with the sizable Class C load. The engine and coach were well-matched for power and weight.
Our overall fuel economy came in at 8.1 mpg, somewhat better than the average we've seen from the old 7.5-liter V-8, over the 270-mile route that included hills, some freeway and a batch of stop-start driving. Ford claims the V-10 can deliver from 13 to 25 percent improved fuel economy, as compared to the 7.5 in similar operating situations.
We were impressed with the new V-10's performance. It toted the load with ease and has the potential for improved fuel-economy figures, which, while moderate at best, can add up in the long run.
