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7 Non-Engine Technologies
Pages 99-117

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From page 99...
... New transmissions with more gears or that are low Cd (below 0.25) are usually specialty vehicles (e.g., continuously variable improve power train efficiency.
From page 100...
... , interior body design. The unibody design is a construction technique seating and trim components, glass, power train components that uses the internal parts as the principal load-bearing (engine, transmission, etc.)
From page 101...
... vehicles tend to be space frame designs, but these are low • Space frame -- usually an aluminum-based structure volume due to cost. The unibody design was developed (aluminum castings, extrusions, and sheet)
From page 102...
... program at the United States Council for Automotive Research (USCAR) indicates that the price of carbon fiber has Non-Body Mass Reduction to fall to $5 to $7 per pound (about 50 percent)
From page 103...
... Underinflated tires increase rolling resistance. The drag brakes reduce the sliding friction of disc brake pads opportunity to improve fuel economy by reducing rolling on rotors when the brakes are not engaged because the resistance is already used by OEMs to obtain better "EPA brake pads are pulled away from the rotating rotor.
From page 104...
... Research is directed primarily at new mafect fuel economy. Reducing tire inflation levels increases terials with higher "thermoelectric figure of merit" (Heremans rolling resistance, which in turn increases fuel consump- et al., 2008; Hussain et al., 2009)
From page 105...
... Nonetheless, are also being reduced, thus further improving power train for both CI and SI engines, fuel consumption is reduced efficiencies. by moving to higher-torque and lower-speed regions of the In addition to planetary-based automatic transmissions, engine maps because the relative effect of engine friction advanced versions of manual transmissions are also be- losses is reduced.
From page 106...
... is take care of the power train efficiency it is necessary, at the reducing pumping losses. Many of the technology measures same time, to downsize the engine and/or change transmisdiscussed in Chapter 4 reduce pumping losses in one way or sion shift points, because with a lighter load, the efficiency another.
From page 107...
... This discrepancy (range mass reduction be significant, a secondary benefit can of fuel economy impact) in fuel economy improvement inaccrue from reducing the size of the needed power train, creases for different vehicle types as the reduction in mass braking systems, and crash management structures.
From page 108...
... . Again as discussed above under "Aerodynamics," if a re Transmission Technologies duction in rolling resistance is combined with a reduction in aerodynamics and mass, the power train can be significantly Fuel consumption reductions generally increase with modified to improve efficiency.
From page 109...
... ered a "freshened" or "re-skinned" model. The ability to An important consideration for introducing new technolo- significantly influence vehicle performance (e.g., through gies that have broad impact concerns the product develop- light-weighting, changing power trains, etc.)
From page 110...
... ; possible impact with aerodynamics, tires, and vehicle accessories Re-engineer 4-8 Extensive makeover of vehicle's platform, Moderate Mass reduction opportunity with Very high chassis, and components to reduce noise, (7-14%) part-by-part material substitution vibration, and harshness and improve (e.g., aluminum or high-strength qualities such as ride, handling, braking, steel)
From page 111...
... . Table 7.7 provides an overview of monitors to warn the driver of underinflated tires for safety the timelines for the introduction of new materials for vari- and fuel economy.
From page 112...
... front suspension subframe, suspension subframe, bumper Brackets Instrument panel bumper beams, cross- beams, rear suspension Crash structures Bumpers members, brackets and knuckles, steering hanger Intake manifold Trim reinforcements, exterior beam, power train components Engine parts (intake manifold, cover, body panels, body side ring, (castings) , condenser/radiator etc.)
From page 113...
... . Mass reduction in other vehicle systems The incremental cost for low-rolling-resistance tires is essuch as power train, wheels, chassis, and interior would typi- timated to be $2 to $5 per tire, but there is some evidence that cally come at similar or slightly higher incremental cost per suggests that these tires may slightly compromise stopping pound saved.
From page 114...
... changes that do not involve reengineering the vehicle can Although DCT units have been in high-volume produc be implemented within a 2- to 4-year time frame. This tion for a number of years, until recently only the VW-Audi could include efforts such as aiming for minor reductions group, working closely with one supplier, has produced such TABLE 7.9 Estimated Incremental Costs for Vehicle Accessories That Improve Fuel Consumption Description Source of Cost Estimate Estimate HVAC -- variable stroke, increased efficiency (humidity control, paint, glass, etc.)
From page 115...
... This could include resizing the power train/ diminishing returns. Planetary-based automatic transmistransmission or aggressively reducing mass (e.g., changing sions can have five, six, seven and eight speeds, but with the body structure)
From page 116...
... Presentation to the Committee for the Assessment of offer the greatest opportunity for implementing new fuel Technologies for Improving Light-Duty Vehicle Fuel Economy, June 3, saving technologies, and this can occur from 4 to 8 years Washington, D.C. after initial introduction.
From page 117...
... 2007. Impact of Vehicle Weight Reduction on Fuel Economy Conjunction with Alternative Power Train Technologies in Automobiles.


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