Primer on Automobile Fuel Efficiency and Emissions - Pollution Probe

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Turbocharging and Supercharging Most internal combustion engines are naturally aspirated, meaning that the air is drawn into the cylinder via the vacuum created by the downward stroke of the piston. Because air is a reactant, the amount of reaction (combustion) that can occur is limited by the amount of air that can enter the cylinder. Turbocharged and supercharged engines have devices that pump more air into the cylinder, allowing for more fuel to be combusted, generating more power. The result is that a smaller displacement engine can produce equivalent power to its larger, naturally aspirated counterpart. Turbocharger: A turbocharger uses the engine exhaust to spin a turbine. The turbine, in turn, drives an impeller, which pumps air into the cylinder. The turbocharger boosts power at higher engine speeds and has a slight lag since sufficient pressure must first build in the engine exhaust stream. The Volkswagen TDI engines are equipped with turbocharger technology. Supercharger: As with a turbocharger, superchargers use an impeller to pump air into the cylinder, but it is powered by the crankshaft rather than the engine exhaust. This adds an extra load to the engine; engineers call this a parasitic load, since it steals power that would otherwise be delivered to the wheels. This limits its fuel consumption benefit in comparison to a turbocharger, which is not connected to the crankshaft. A supercharger, however, can boost power at lower engine speeds with no lag. The Pontiac Grand Prix GTP uses supercharger technology. 47 Chapter 3 | Increasing Fuel Efficiency by Improving Automobile Technology
During the late 1970s and early 1980s, North American automobiles, on average, experienced significant engine downsizing in an attempt to curb fuel consumption (more on this in chapter five). Many models that were formerly equipped with 8-cylinder engines now came equipped with 6- or 4-cylinder engines. Power output of engines decreased and vehicles became smaller (lighter cars require less power to accelerate, and lose less energy upon braking); however, this trend only lasted for a few successive model years. New technologies were soon introduced that allowed smaller engines to produce more power without increasing the amount of fuel consumed. These technologies included fuel injection, improved combustion chamber design, increased compression ratios, more precise valve control, and exhaust gas recirculation. This ensures more complete combustion of the fuel, thus increasing the amount of power produced from each drop of fuel and, depending on the technology, reducing the amount of NOx and VOCs (HC) emissions. More efficient engine design meant newer vehicles could meet the demand for power with smaller engines. The smaller engines also represent a significant reduction in weight, contributing to lower fuel consumption. Since the mid-1980s, engines continued to become more efficient producers of power. This would have led to greater fuel savings if the engine downsizing trends had continued. Instead, engine sizes remained steady and reductions in fuel consumption were not realized. Ongoing technology improvements led to ever-higher power ratings among new vehicles (see Figure 3-1). For future vehicle fleets to consume significantly less fuel, smaller engines will need to be part of the design agenda among automakers. In September of 2008, General Motors announced that they would double their global production of small four-cylinder engines (1.0 to 1.4 litres) by 2011, with more than half of the increase happening in North America. The highlight of this plan is the manufacturing of a 1.4 litre turbocharged engine, generating the power of a larger engine but consuming the fuel of a small automobile. There are numerous engine technologies available today (or in development) that will enable a small engine to perform as would a larger engine in terms of power output, while consuming much less fuel. These technologies, along with potential fuel consumption reductions, are listed in Table 3-2. It should be noted that these potential reduction factors are not necessarily additive, nor are they necessarily compatible with each other. <strong>Primer</strong> on Automobile Fuel Efficiency & Emissions 48
Page 1 and 2: PRIMER ON AUTOMOBILE FUEL EFFICIENC
Page 3 and 4: POLLUTION PROBE’S PRIMER SERIES P
Page 5 and 6: JUNE 2009 Pollution Probe is please
Page 7 and 8: D R A F T C O P Y D R A F T C O P Y
Page 9 and 10: Chapter 5 BACKGROUND ON FUEL EFFICI
Page 11 and 12: CHAPTER 1 | EMISSIONS FROM AUTOMOBI
Page 13 and 14: ways to power automobiles, such as
Page 15 and 16: In the real world, however, combust
Page 17 and 18: TABLE 1-1, CONTINUED OXIDES OF NITR
Page 19 and 20: TABLE 1-1, CONTINUED OXIDES OF SULP
Page 21 and 22: This “enhanced greenhouse effect
Page 24 and 25: CHAPTER Chapter 2 TWO D R A F T C O
Page 26 and 27: BOX 2-1 Fuel economy improvements v
Page 28 and 29: Five Automobile Subsystems, continu
Page 30 and 31: Five Automobile Subsystems, continu
Page 32 and 33: % Energy Flow Within A Vehicle (val
Page 34 and 35: % % % % How an Internal Combustion
Page 36 and 37: The higher the compression ratio of
Page 38 and 39: Major forces on an automobile in mo
Page 40 and 41: Inertia To increase speed, the engi
Page 42 and 43: CHAPTER THREE INCREASING Chapter 3
Page 44 and 45: Vehicle Weight, Safety and Fuel Eff
Page 46 and 47: FIGURE 3-1 Engine Size: Power versu
Page 50 and 51: Table 3-2: Engine Technology and Fu
Page 52 and 53: Gasoline versus Diesel engines: Gas
Page 54 and 55: Reducing Drivetrain losses The Tran
Page 56 and 57: call parasitic loads on the cranksh
Page 58: Hybrid Electric Vehicles Today, the
Page 61 and 62: Parallel Architecture Internal Comb
Page 63 and 64: these battery options is expected t
Page 65 and 66: CHAPTER 4 | WHAT YOU CAN DO TO MAXI
Page 67 and 68: A poorly operating Emission Control
Page 69 and 70: Table 4-2: Aerodynamics and Roof Ra
Page 71 and 72: Plan trips wisely. When doing erran
Page 73 and 74: Consider your fuel options. Unless
Page 76 and 77: Purchasing a Vehicle When it comes
Page 78 and 79: A fuel consumption gauge is an inst
Page 80 and 81: CHAPTER FIVE BACKGROUND ON FUEL EFF
Page 82 and 83: and heavy. On average, the 1974 mod
Page 84 and 85: Fuel Efficiency Trends As discussed
Page 86 and 87: Table 5-1: CAFC Targets CAFC Standa
Page 88 and 89: egulations have been implemented wi
Page 90 and 91: U.S Federal Tier 1 Emissions Standa
Page 92: Table 5-3: California LEV II Emissi
Page 95 and 96: CHAPTER 6 | WHAT IS BEING DONE BY G
Page 97 and 98: Table 6-1: Green Levy Tax Rates Com
Page 99 and 100:
ONTARIO Sales Tax Rebate — People
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sideration that will force automake
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of about €5,000 (CA$8,400) for th
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CHAPTER 7 | WHAT NEEDS TO BE DONE E
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EcoMobility for a Cleaner Environme
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This should also benefit automakers
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TORONTO OFFICE: 625 Church Street S
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Primer on Automobile Fuel Efficiency and Emissions - Pollution Probe

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