Vehicle Accessories

Table 7.9 shows the committee’s estimates of the costs for vehicle accessories that could improve the fuel consumption of light-duty vehicles.

Transmission Technologies

The estimated retail price equivalent for each transmission technology is provided in Table 7.10. As was the case for the engine technology chapters (e.g., Chapters 4 and 5), the baseline for transmission costs is the 4-speed automatic typical of 2007 model-year vehicles. Cost estimates are from the two sources considered (EEA, 2007; Martec Group, Inc., 2008). As can be seen from Table 7.10, the cost estimates for the 5-, 6-, 7-, and 8-speed automatic transmission replacements for the baseline 4-speed automatic have a considerable numerical range. In addition to the cost estimates, Table 7.10 also includes cost estimates converted to RPE using the RPE multiplier of 1.5. Besides the estimates for 5-, 6-, 7-, and 8-speed automatic transmission replacements, estimates are also included for DCTs and CVTs. The DCT estimates reflect an even wider numerical range than those for the automatics. For example, the 6-speed automatic cost estimates range from $133 to $215, whereas the estimates for the wet-clutch, 350 N-m torque capacity range from $140 to $400.

Although DCT units have been in high-volume production for a number of years, until recently only the VW-Audi group, working closely with one supplier, has produced such a transmission. As a result, the number of cost estimates available to the committee was limited. When additional information was sought by the committee, the results reflected the still-emerging knowledge base about this transmission type. One estimate, based on a detailed teardown study conducted by FEV, Inc., for the EPA, estimated the cost of 6-speed DCTs with 350 N-m torque capacity and wet clutches at over $147 less than that for a 6-speed automatic (Kolwich, 2010). However, OEMs considering tooling up their own equivalent units had also made careful estimates of the high-volume piece cost increase of DCT6s. These OEM estimates were that high-volume DCT6s would cost nearly $200 more than 6-speed automatics. Thus, the range between estimates was approximately $350. At the present time, insufficient information is available to narrow this wide range.


There is a range of non-engine technologies with varying costs and impacts to consider. Many of these technologies are continually being introduced to new vehicle models based on the timing of the product development process. Coordinating the introduction of many technologies with the product development process is critical to maximizing their impact and minimizing their cost. Relatively minor changes that do not involve reengineering the vehicle can be implemented within a 2- to 4-year time frame. This could include efforts such as aiming for minor reductions

TABLE 7.9 Estimated Incremental Costs for Vehicle Accessories That Improve Fuel Consumption


Source of Cost Estimate


HVAC—variable stroke, increased efficiency (humidity control, paint, glass, etc.)

U.S. Environmental Protection Agencya


Electric and electric-hydraulic power steering

Deutsche Bank


Thermoelectric energy recovery


Several hundred dollars

aThe U.S. EPA has estimated the cost associated with improving the energy efficiency of the A/C system and reducing refrigerant leakage from the system at less than $110 to the consumer (ANPR-HQ-OAR-2008-0318; FRL 8694-2). With an RPE of 1.75 the cost to the original equipment manufacturer would be just over $60.

TABLE 7.10 Estimates of Replacement Costs for Transmission Technologies Relative to 2007 4-Speed Automatic Transmissions

Transmission Type

$Cost (EEA, 2007)

$RPE (EEA, 2007)

$Cost (Martec, 2008)

$RPE (Martec, 2008)

5-speed automatic



6-speed automatic





7-speed automatic



8-speed automatic



DCT (dry clutch, 250 N-m)



DCT (wet clutch, 350 N-m)





CVT (engine <2.8 liter)



CVT (engine >2.8 liter)



NOTE: RPE values were determined using a cost multiplier of 1.5.

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