Volvo Trucks' 2007-model diesels will include three displacements and 22 ratings from 325 to 600 horsepower, all replacing its current model and one designated to go in its vocational VHD truck and tractor.
Most engines will be more fuel efficient than the current D12, but the high cost of developing the products to meet stricter exhaust emissions limits will be passed on to customers via a $7,500 per truck surcharge, the builder's executives said. By federal fiat, all '07 diesels begin production after Jan. 1, so will begin showing up in '07 trucks a month or two after that.
The new engines will include a D11 and D13, which will replace the current D12 by year's end, and the previously introduced D16. The D13 is the only engine to be offered in the vocational VHD series. Volvo will continue to offer the Cummins 15-liter ISX in '07 form in certain truck models.
The 12.8-liter D13, which will be Volvo's highest-volume engine model, will have eight ratings from 335 to 485 horsepower and 1,350 to 1,650 lbs.-ft. It weighs 2,550 pounds dry and will be used in VN tractors and in the VHD truck and tractor. The 10.8-liter D11 will come in seven ratings from 325 to 405 horsepower and torque of 1,250 to 1,450 lbs.-ft. At 2,175 pounds dry, it will be Volvo's lightweight engine and offered in VN highway tractors.
The 16.1-liter D16, introduced a year ago, will continue with updates for '07. It will have seven ratings from 450 to 600 horsepower and 1,650 to 2,050 lbs.-ft. Maximum horsepower will be 25 less than now and top torque will be down by 200 lbs.-ft because of the turbo's limited ability to deliver inlet air at '07 specifications. As now, the D16 will be available in long-hood VN highway and VT heavy-haul tractors. It weighs 3,070 pounds.
Volvo's diesels use the same "architecture" as MP series engines previously announced by Mack Trucks, Volvo's sister company. The two companies' engines will differ in operating characteristics, but all will be built at Volvo Powertrain's Hagerstown, Md., factory, which was refitted to produce them.
Like the D12, Volvo and Mack's new engines will use a variable geometry turbocharger with a sliding nozzle, an overhead camshaft, four valves per cylinder, one-piece rigid-deck cylinder head, and dual-solenoid fuel injectors.
To these were added a viscous damper on the camshaft and rear-mounted gear drain, which absorb torsional vibrations and route them to the flywheel; ultra high-pressure fuel system, with fuel injected at up to 35,000 psi; "precision flow" exhaust-gas recirculation, with a low-mounted jacket-water gas cooler; and steel "ladder" reinforcement of the main bearing area to handle higher combustion pressures.
There'll also be a dual-element diesel particulate filter, or DPF, which doubles as a muffler. This includes an oxidation catalyst to neutralize carbon monoxide, a "monolith" filter to strip out soot particles, temperature sensors to monitor regeneration that burns off the particulates, and inlet and outlet modules.
Mack will also use this DPF, which will be made by Fleetguard. The device will be offered as a stack-mount unit and a "compact" version that will hang on the frame under the hood, just behind a truck's right-front tire.
Regeneration to burn off soot will occur passively, accomplished by high exhaust heat as the truck goes down the road, and actively, by using small injections of diesel fuel. Ash particles from motor oil will also accumulate in the filter, and will have to be periodically removed by compressed air in a special machine. This will require removing the DPF for servicing every 100,000 to 200,000 miles, depending on how the truck operates.
All models will need ultra low-sulfur diesel fuel to allow DPFs to live and meet the upcoming exhaust emissions limits. These will lower nitrous oxide, particulates and other exhaust ingredients by 90 percent or more.
Common architecture and design among the three engine models, and even some common parts, will allow technicians to service and repair the diesels using similar techniques, Volvo executives said. Reduced service and repair times should result from placement of parts and components for easy access and replacement.
Oil-drain intervals are up to 30,000 miles for the D11, up to 45,000 miles for the D13, and up to 50,000 miles for the D16. All will require CJ-4 motor oil, a new type that, like the ultra low-sulfur fuel, will be available later this year.