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Economies of (drivetrain) scale

  • Magazine Feature Article
  • OFHDEC07_01
Published December 01, 2007 by SAE International in United States
Language:
  • English

Emissions challenges continue, but engine and transmission technology is advancing solutions and improving vehicle systems integration.

Balancing requirements for improved productivity and operators' needs against ever-increasing environmental and safety legislation is an enduring challenge for off-highway powertrain engineers. As advances are made and solutions resolved, there is the added complexity of the evolution of the powertrain itself to consider: power and torque are increasing, engines run hotter, new fuels and lubricants are developed. But to counter this, some of the advancing technology is easing the engineers' lot: manufacturing tolerances continue to improve and higher software processing speeds are enhancing engine management.

The scale of the task that must be faced can be appreciated by the requirements of the U.S. Environmental Protection Agency's stringent Tier 4 emissions regulations to be phased in between 2008 and 2014. This move toward cleanliness is evidenced across the world. In October this year, China set standards similar to those of Europe's Tier 1 and Tier 2 for off-highway mobile diesels, with the introduction of the Limits and Measurement Methods for Pollutants from Diesel Engines of Non-Road Mobile Machinery (1,11) GM 20891-2007.