The cost of meeting standards for conventional pollutant emissions is a perennial bone of contention in arguments over vehicle emission regulations. The public health benefits of the most stringent standards have been repeatedly and conclusively demonstrated, and the control technologies are readily available. Nevertheless, countries with the largest vehicle markets worldwide differ greatly in the rates at which they are willing to adopt the most stringent emission standards—and some of those whose populations would benefit most lag furthest behind the best achievable standards. Among the reasons often given for delaying the implementation of stricter standards is the extra cost added to the vehicle by the emission control system.
This new report finds that the cost concerns are overstated, in great part because cost estimates used in setting early standards in the U.S. and EU have never been updated to reflect actual experience and incorporate the substantial improvements in emission control technologies and reductions in cost that have occurred over time. The report assesses the costs of required technologies in current terms, using both direct and indirect methods to account for technology changes, correct for inflation, and pull in feedback from manufacturers.
The report uses U.S. and EU regulatory programs to estimate costs because detailed information for those programs is widely available. Since most countries/regions have modeled their own regulatory programs on one or the other of these approaches, the technology steps are very similar and so the cost findings in this report can be used as reasonable, conservative benchmarks outside the U.S. and Europe.
Diesel and gasoline vehicles are assessed separately, and the cost of complying with emission standards differs significantly between them. For example, the cost of taking a 4-cylinder 1.5L gasoline engine from no emission controls to the most stringent proposed EU standard (Euro 6) is around US$360, whereas the cost of taking a 4-cylinder 1.5L diesel engine from no emission controls to Euro 6 standard is around $1400.
Emissions from gasoline engines can be reduced to very low levels through precise air-fuel control and catalytic aftertreatment. These are mature technologies with modest incremental compliance costs for even the most stringent existing standards. Controlling emissions of nitrogen oxides (NOx) and particulate matter (PM) from diesel engines is more complex and requires a combination of technologies for air management, fuel injection control, aftertreatment, and system integration, which carry substantially higher costs relative to gasoline engine controls.