THE NATURAL GAS SELECTION. ALLISON AUTOMATICS. The Natural Advantage Why Allison Automatics Are The Preferred Choice For Natural Gas For over 60 years, Allison fully automatic transmissions have proven to be the most reliable, productive and trouble-free transmissions in commercial trucking. Now with the increasing appeal of natural gas, savvy fleet operators are specifying Allison Automatics for their natural gas-powered vehicles. Allison Automatics are perfectly suited for natural gas, both compressed (CNG) and liquefied (LNG), powered vehicles in a wide range of applications because of the inherent benefits of Allison’s patented torque converter technology and full-power shifts. Did you know most North American and European natural gas-equipped commercial vehicles come standard with an Allison fully automatic transmission? Natural Gas-Powered Commercial manuals require the engine to be at zero torque. With an Vehicles Get Work Done automated manual, the driver’s foot is fully engaged on the pedal during the upshift; however, the controls automatically Natural gas-powered commercial vehicles are work trucks. reduce engine torque to zero to make the shift and interrupt Trucks that need to complete their task while minimizing power to the engine. cycle time. This is accomplished by getting horsepower to the wheels in the most fuel efficient manner at every stage of the duty cycle. While fuel efficient, natural gas More Power to the Wheels engines are characterized by a slow torque response that Because the natural gas engine torque response results in a makes commercial vehicles lose efficiency and productivity. longer torque interruption time, manual transmissions and An Allison transmission featuring our industry-leading automated manuals are usually not the best choice for use torque converter can make these obstructions to the with natural gas engines. To get equivalent power from this work process a non-issue. type of engine, it must run at higher speeds which can result in reduced bearing life and increased clutch wear in manual Full-Power Shifts and automated manual transmissions. Allison Automatics, with their full-power shift advantages, provide smooth, seamless shifts, which do not require the Allison’s continuous, full-power shifts are not impacted by engine to go to zero torque, so the slower response time-to- the slower torque response time of a natural gas engine and throttle cycles usually associated with a natural gas-powered deliver more power to the wheels than manual or automated vehicle are no longer an issue. Manuals and automated manual transmissions during vehicle acceleration. Improved Startability Better Braking Capability Torque multiplication accomplished via the Allison torque Some natural gas engines do not offer an engine brake and converter compensates for the reduced torque and horsepower others have considerably less engine braking torque available delivered by natural gas engines providing improved startability compared to a diesel engine due to the natural gas engines’ while eliminating clutch slippage. Even starting on steep grades is inherent design. The addition of a retarder on an Allison not a problem. easily solves this problem. How An Allison Transmission Helps Your Natural Gas Engine Perform NON-ALLISON TRANSMISSION THE ALLISON TRANSMISSION ADVANTAGE WHAT THIS MEANS FOR THE CUSTOMER Transmission launches at higher engine Launching is equivalent to launching Lower Clutch Engagement Torque speeds leading to more power a diesel-powered vehicle Wet, hydraulically-controlled clutches Upshifts and powered downshifts not Slower Torque Response pull down engine during upshifts impacted by slower torque response Lack of torque interrupts during shifts Productivity not impacted by a potentially Lower Torque Density enables lower torque engines to perform lower rated engine Allison 3000/4000 series transmissions Reduced Exhaust or Compression Braking Enhanced safety and reduces service have an optional integral output retarder Leads to increased operation Poor BSFC at Light Engine Loads Enables engine downsizing at more efficient conditions “By the end of the year, we’re going to have 100 trucks running with natural gas. And one of the best parts about them is the Allison 6-speed automatic transmission.” Mike DelBovo, President, Saddle Creek Transportation Patented Torque Converter Technology Torque Converter Benefits The heavy-duty Allison torque converter is at the heart of • Startability allows vehicle launch at peak torque of the engine what makes an Allison Automatic the most effective, efficient, • Uses full engine torque and multiplies it and productive commercial transmission in the world. • During launching, more efficient than a starting clutch Increased performance, faster acceleration, greater operating with no clutch slippage flexibility, and virtually no rollback are all advantages provided • No wear on components which means extended product life and reduced downtime by Allison’s torque converter. • Very productive in stop and go traffic • Acts as a variable first gear which can more than double engine torque at launch Learn More About The Natural Advantage allisontransmission.com/naturaladvantage Allison Has You Covered Our extensive network of over 1,200 authorized Allison Distributors and Dealers in North America means convenient, factory-quality Allison Transmission service is always close at hand. www.allisontransmission.com P.O. Box 894, Speed Code PF3 SA7250EN (2014/04) Indianapolis, Indiana 46206-0894 ISO/QS 9000 and ISO 14001 Certified Information or specifications subject to © 2014 Allison Transmission, Inc. change without notice or obligation. All rights reserved..