Source: CP staff
Diesel engines meeting lower Environmental Protection Agency (January 2010) thresholds for particulate matter (PM) and oxides of nitrogen (NOx) emissions will soon accompany most new heavy-duty trucks spec'ed for mixers, dumps and concrete product hauling. Caterpillar Engine Division's retreat from on-highway offerings, coupled with model overhauls driven by EPA 2010-complaint enginesÌ cooling requirements and added exhaust treatment components, has realigned power specifications.
Daimler Trucks North America and Paccar Inc. have integrated their own engines, the (Detroit Diesel) DD13 and MX, respectively, into the Freightliner and Western Star, plus Kenworth and Peterbilt lines. Cummins Inc. has tooled the new ISX 11.9, and a modified ISL, for a range of heavy duty models. Mack Trucks entered the EPA 2010 phase with the MP diesel engines, continuing a well established model of integrated power and vehicle offerings. The DD13, MX, ISX and MP deploy Selective Catalytic Reduction (SCR) and branded diesel exhaust fluid (urea) treatment to attain the EPA emissions thresholds. Navistar Inc. has opted for a different path to EPA 2010 compliance, engineering its severe service models around the MaxxForce engine package.
The ISX 11.9 rounds out the manufacturer's 2010 heavy-duty engine line, as full production commenced in August following the model's Environmental Protection Agency and California Air Resources Board certification. A mixer- and dump-suited ISM engine successor, the engine and its exhaust treatment components meet EPA 2010 NOx and PM thresholds of 0.2 grams and 0.01 grams per brake-horsepower-hour, respectively. The ISX 11.9 is offered in 310-450 hp and 1150-1650 lb-ft torque ratings, with optional features including single- and dual-cylinder air compressors; Front Engine Power Take-Off; and, an enhanced Rear Engine Power Take-Off for customers who need to maximize payload.
Like the well-traveled ISX15, the 11.9 uses an enhanced cooled Exhaust Gas Recirculation system; single VGT Turbocharger; and, proprietary Xtra-High Pressure Injection (XPI) fuel system, enabling controlled fuel injection events and yielding up to 5 percent better fuel economy than pre-2010 models. Both engines attain EPA 2010 emissions compliance through the Cummins Aftertreatment System with SCR technology.
Daimler Trucks North America
The company is positioning the Freightliner brand for stronger presence in construction through the M2 model, picking up where the discontinued Sterling brand left off and replacing the FL series. A new Coronado SD, especially suited for dumps, replaces the FLD. Daimler's Detroit Diesel unit has developed the DD13 engine in power and torque ratings suited to mixers and dumps, especially those mounted on M2 and Coronado trucks. The 12.8-liter DD13 replaces MBE4000 and features a six-cylinder, in-line configuration. It will be offered in output and torque variants from 350 to 470 hp and 1,250 to 1,650 lb-ft.
Built to spend more time in top gear, the DD13 pulls strong down to 1,100 RPM, which results in increased fuel economy. Its enhanced cooling system reduces fan on-time, further contributing to the engine's fuel efficient design. Another key feature is the electronically-controlled Amplified Common Rail Fuel System, a delivery component working with Detroit Diesel's DDEC VI engine management system to deliver the exact amount of fuel needed at just the right moment, creating an optimal combustion event.
The result is a more fuel-efficient engine, company engineers note, and a reduction in NOx emissions without draining power. The DD13's torque curve provides an extremely wide peak torque range, up to 500 rpm, allowing drivers to locate with ease the Îsweet spotÌ for optimum engine performance. The new engine is EPA 2010-compliant through the Blu-Tec SCR technology.
Mack Trucks Inc.
Granite series-suited MP7 engines feature the ClearTech SCR system, EPA 2010-certified and delivering near-zero emissions. Mack was the first heavy-duty truck and engine manufacturer to achieve agency compliance certification, notes Senior Vice President, Sales & Marketing Kevin Flaherty, adding, We had trucks in customer hands early and often for testing, and were ready to go soon enough to start [fall 2009] production.
The ClearTech diesel emissions control system uses SCR to reduce NOx output to near-zero, while improving fuel economy by up to 5 percent and reducing active regenerations of the diesel particulate filter. ClearTech injects diesel exhaust fluid (DEF)Ûa non-toxic solution of ultrapure water and urea, a common nitrogen-bearing compoundÛinto the engine's exhaust stream. DEF works with the hot exhaust and a catalyst to convert NOx into nitrogen and water vaporÛharmless and natural components.
International trucks, including the WorkStar 7600 and PayStar 5000 series, will meet 2010 EPA diesel engine emissions requirements with MaxxForce Advanced EGR (exhaust gas recirculation) engines. An emissions reduction technique already used in most gasoline and diesel engines, EGR works by re-circulating a portion of an engine's exhaust back to the engine cylinders and burning off excess pollutants.
When temperatures in the combustion chamber get hot, NOx forms and, when combined with hydrocarbons, yields smog. EGR re-circulates this exhaust into the intake stream. Since the exhaust gases have already combusted, they donÌt burn again. These gases displace some of the normal intake, slowing and cooling the combustion process, which reduces NOx formation. The 2010 MaxxForce are engineered to precisely control the flow of re-circulated exhaust. The engines have increased injection pressure, improved combustion and refined calibrations with that goal in mind. The result is an engine that treats NOx in-cylinder, and therefore requires no extra exhaust treatment effort from truck operators.
Scheduled for production at a new Mississippi plant, the MX will be available on models most commonly ordered for mixer and dumps: the Kenworth T800 and W900 and Peterbilt 365 and 367. The 12.9-liter engine has a 380hp-485hp range and torque outputs up to 1,750 lb-ft. Fuel efficiency, durability and lightweight design, Paccar notes, position the MX for vocational and over-the-road models. It meets EPA 2010 diesel engine emission guidelines through SCR technology, which requires an additional treatment chamber, coupled with a small quantity of urea or diesel exhaust fluid, beyond the diesel particulate filter of EPA 2007 emissions solutions.
The construction-grade Kenworth T440 and T470 models, engineered as heavy Class 7 or light Class 8 vehicles, will be available with Paccar PX-8 (or Cummins ISL9) in 260-380 hp ratings, both meeting EPA 2010 emissions compliance with exhaust configurations mirroring the MX (and Cummins ISX11.9).