European automakers call for increase in acceptable emission levels
European, Asian, and North American automakers have all had their cars tested for decades to try to ensure they meet exhaust emission limits, as measured by strict standardised vehicle tests on dynamometers, or "rolling roads." However, on the back of the Volkswagen diesel scandal, American and European regulators now plan to test more cars under real-world conditions to measure their on-road emissions. If that happens, European makers say, the legal limits for emissions of nitrous oxides, or NOx (which is the substance VW's diesel TDI cars cheated on), must be raised significantly, by as much as 70% from today's levels. As the New York Times states:﻿﻿ "﻿t﻿he automakers…are essentially conceding what outside groups have said for some time — that the industry cannot meet pollution regulations when cars are taken out of testing laboratories.”

LONDON — Despite the cloud cast by the Volkswagen scandal, automakers are proposing that they be allowed a 70 percent increase in the nitrogen oxides their cars emit, unreleased documents show, as part of new European pollution tests.

Under the new plan, cars in Europe would for the first time be tested on the road, using portable monitoring equipment, in addition to laboratory testing.

The automakers, which include Volkswagen, General Motors, Daimler, BMW, Toyota, Renault, PSA Peugeot Citroën, Ford and Hyundai, are essentially conceding what outside groups have said for some time — that the industry cannot meet pollution regulations when cars are taken out of testing laboratories. The move is occurring as Volkswagen, the world’s largest automaker, grapples with fallout from the discovery that 11 million of its vehicles were equipped with software meant to cheat emissions tests.

Tests of car emissions required in the United States and Europe take place in laboratories, where vehicles are run through drills on a dynamometer, which is the automotive equivalent of a treadmill. Automakers have found ways to cheat the tests since emissions were first regulated in the early 1970s.