Emissions and Fuel Economy of Vehicles and Engines in the Real World and On the Road

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Emissions and Fuel Economy of Vehicles and
Engines in the Real World and On the Road
Leo Breton Mechanical Engineer
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Computer-Controlled Vehicles/Engines

• All New On-Road Vehicles
• Growing Non-Road Presence
• Offer Great Potential to Improve Fuel Economy and
  Reduce Emissions
• But Often Perform Differently in Real World
  Compared With Laboratory
• Certification Process Used for Establishing
  Performance
• Lab Testing Limitations
• Engine Calibration Process
• Manufacturers Seeking Competitive Advantage

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• All New Vehicles and Engines Must Meet Numerical
  Emissions Standards and Must Not Have Defeat
  Devices
• Fuel Economy and Emissions Levels Determined for
  a Vehicle/Engine Through Manufacturer-Run
  Certification Testing With Limitations
• Prototype Vehicle/Engine
• Calibrated to Test Method
• Certification Test Fuel
• Professional Driver/Computer
• Tightly Controlled Drive Cycle
• Laboratory Dynamometer Testing
• Simplified Loading Curve
• Tightly Controlled Ambient Conditions
• Simulated Sensor Inputs for Heavy-Duty

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Lab Testing MethodsChassis Dynamometer
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Chassis Dynamometer Cycles
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Chassis Dynamometer Cycles
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Lab Testing MethodsEngine Dynamometer
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Engine Dynamometer Cycle
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Prohibition of Defeat Devices

• No new gasoline-fueled light-duty vehicle or
  light-duty truck shall be equipped with a defeat
  device.
• Defeat Device means an auxiliary emission
  control device (AECD) that reduces the
  effectiveness of the emission control system
  under conditions which may reasonably be expected
  to be encountered in normal vehicle operation and
  use, unless
• Conditions are also substantially included in
  federal test procedures
• Need is justified to protect vehicle against
  damage or accident
• Needed for engine starting

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Manufacturer Fueling Calibration
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Manufacturer Fueling Calibration

• Fueling Matrix a Function of Lab Limitations
• Ambient Temp 68-86 F
• Coolant Temp Lab Temp, Cycle, Cooling
• Manifold Pressure Lab Altitude, Cycle
• Throttle Position Altitude, Cycle
• Throttle Rate of Change Professional Driver
• Vehicle Speed Cycle
• Engine Speed Cycle
• Engine Speed Change Cycle, Driver
• A/C On/Off

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• Measuring Emissions and Fuel Economy in Real
  World
• Traditional Equipment Massive / Power Intensive
• Auto Industry Considered it Impossible
• EPA Didnt See Fit With Regulatory Framework
• Nobody Knew What Was Being Missed
• Nobody Thought About It
• ROVER Developed to Demonstrate It Was Possible
• ROVER Patent is Basis for Commercial Systems

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ROVER Light Duty Installation
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ROVER HD Installation
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ROVER HD Installation
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What Has Been Found In Real World?

• Emissions Higher Than Expected
• Fuel Economy Lower Than Expected For Passenger
  Cars Even On Same Cycle as Lab
• Engines/Vehicles Often Behave Very Differently
• Sensitivity to Driver Inputs
• Catalyst Protection/Reduced FE Under High
  Loads
• Enleanment to Boost Fuel Economy
• Calibration Space Not on Appearing on Test
• Small Engine Catalyst Protection at Normal
  Highway Speeds
• Heavy-Duty Diesel Improved Fuel Economy on the
  Cheap
• Fuel Economy Had Been Higher Than Expected for
  HDDE With Major Emissions Hit
• Reduced Standards Were No Guaranty Of Reduced
  Emissions

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Typical Passenger VehiclesReal-World Traffic,
Fuel Effects
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Sensitivity to Throttle Movement
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Catalyst Protection
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HDG Enleanment Strategy to Boost FE
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Enleanment Strategy Diagnosis
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Enleanment Strategy Diagnosis
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Calibration Not On Test
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Small Engine EnrichmentHilly Terrain
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Small Engine Enrichment Highway Speeds
3.7 g/mi
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Calibration Not On Test / Small Engine Protection
Fuel Economy Guide 61/70 Hilly Terrain On-Road
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Heavy Duty NOx Standard Experience
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HDD Steady-State Fuel Economy Strategy On the
Cheap
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HDD Steady-State Fuel Economy Strategy
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HDD Steady-State Fuel Economy Strategy
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Conclusions and Comments

• Laboratory Testing Cycles Are Easily Defeated or
  Calibrated Around
• Laboratory Data Has Not Been a Good Predictor of
  In-Use Performance
• Laboratory Data Makes Bad Models and Leads to
  Bad Inventories
• Regulations Do Not Work Without Effective In-Use
  Compliance Testing
• In-use Fuel Economy is Significantly Lower Than
  Label Even With Similar Drive Cycle
• AECDs (Deliberate Calibration Strategies) Can Be
  the Dominant Factor in Real-World Performance
• Increasingly Sophisticated Fueling Strategies
  are Likely to Show Up Over Time

Will Real-World Fuel Economy Increase
Proportionately to CAFE Figures? Are CAFE Figures
a Good Basis for Energy Analysis? Dont We Need a
Good Understanding of Real-World Fuel Economy To
Become More Energy Independent?