On Wednesday, Greg Archer the Clean Vehicles Manager at Transport and Energy, wrote that the emissions testing cheating scandal at Volkswagen is just the tip of the iceberg. He referred back to a report published last week by T&E, Don’t Breathe Here, detailing how European emissions testing procedures are completely inadequate. Most importantly, they found that 9 out of 10 diesel vehicles (90%) in Europe fail emissions tests performed in real world driving conditions, while passing the laboratory test. The problem is not limited to Volkswagen, but affects every manufacturer, and to a lesser extent also affects gasoline powered vehicles where 4 out of 5 (80%) fail emissions tests on the road, while passing laboratory tests.
The T&E report describes Europe’s NEDC procedures as being more lax, and easier to game by manufacturers, than the EPA’s test procedures. The report documents several known methods where manufacturers manipulate laboratory test results to make emissions look better than real world driving conditions. The result is emissions testing that T&E describes as “an ineffective system for testing vehicles that deliver impressive reductions of emissions in laboratory tests but fail to replicate this performance when driven on the road”.
The NEDC procedures contain loopholes that manufacturers routinely exploit to get better results. For example, the manufacturer can fully charge the 12v battery then disconnect the alternator during the test run, thereby reducing energy load on the engine so it runs better. Or they can pull back the brake calipers to reduce drag on the wheels, allowing the engine to run better.
The core flaw, however, is the overall test procedure. The car is put through a standardized, but artificial, sequence of simulated speeds in a test cycle lasting 1100 seconds, where the throttle is ramped up and down to produce the required speeds. T&E points out this subjects the engine to a small subset of engine power levels, and not fully testing the engine. Manufacturers are known to be optimizing engines for good emissions results in the tested power levels, at the expense of emissions at non-tested power levels.
And, according to T&E’s report, manufacturers are known to have software in their engine control systems to detect an emissions test cycle. Or, exactly the allegation levied at Volkswagen by the EPA.
Two upcoming procedures changes will make it harder for automakers to game emissions testing in Europe. The critical one, according to T&E, goes into effect in Europe in 2016, and is a real driving emissions (RDE) test that’s performed on the road. The on-road test more closely represents real-world driving situations in a way artificial laboratory tests cannot. The other change is a new test procedure developed by the United Nations, which goes into effect in 2017 in Europe.
Do these issues apply to the U.S.? The T&E report refers to EPA and CARB test procedures as being far more advanced than what’s done in Europe. However, Volkswagen’s flagrant deceit in filing bogus emissions results raises big questions whether we can trust testing done in America. The test cycle specified by the EPA is just as artificial as the NEDC test cycle, for example, and is also not performed in real world road conditions.
The EPA and CARB have announced they’ll look into emissions from other car manufacturers, while also investigating the wrong-doing by Volkswagen.