AutosNew Diesels in Trouble: Germany's Stricter Emission Tests Challenge

New Diesels in Trouble: Germany's Stricter Emission Tests Challenge

Exhaust emission tests
Exhaust emission tests
Images source: © Mercedes-Benz

5:57 PM EDT, April 23, 2024

As of July 1, 2023, Germany has enforced stricter rules regarding exhaust emissions during technical inspections, putting many nearly new cars at risk of failing these tests.

The revised regulations, now in effect for a year, target diesel vehicles certified under the Euro 6 standard. For these vehicles, the first technical inspection—three years after purchase—may surprise their owners. Despite being relatively new, not all these vehicles meet the stringent criteria.

The German automobile club ADAC highlighted the issue after receiving complaints from several owners of Ford vehicles equipped with the 1.5 TDCi engine and a particulate filter, which failed the exhaust emissions test during the inspection. The core of the problem lies with the particulate filters, which, according to diagnosticians, fail to perform adequately and need replacement. The replacement cost can reach up to 3,000 euros—a significant expense for what are essentially new cars. Ford's German division is currently without an approved replacement filter but is diligently working on a solution.

"The development of software updates, the provision of improved DPF filters, and coordination with the KBA (Federal Motor Transport Authority) are all underway at full speed to address this issue," state the brand's representatives, as quoted by ADAC.

Widespread issue beyond one manufacturer

The complaints initially focused on Ford, but further investigation by ADAC revealed that the issue is more extensive and affects other brands. Data from TÜV, covering 950,809 vehicles inspected from August 1 to October 30, 2023, shows that 32,285 vehicles failed their first technical inspection—a failure rate of 3.4 percent.

Difference between homologation and inspection criteria

The discrepancy between the emissions standards set during the homologation process and those applied during technical inspections is at the heart of the controversy. While homologation considers the number of particulate matter emitted per mile, the technical inspection assesses the concentration of particulate matter in the exhaust gases. TÜV and Dekra officials have pointed out that the current limit—250,000 particles/cm3—is considered high, yet vehicles exceeding this threshold during an inspection are deemed to fail under Euro 6 standards.

Aligning the testing procedures and standards between homologation and inspections might seem like a straightforward solution. However, logistical, financial, and technical challenges make this alignment impractical.

Drivers left with few options

In Germany, vehicle manufacturers must comply with homologation standards, which may not align with the criteria used during technical inspections. This disparity leaves owners of nearly new diesels that fail their first inspection due to emissions in a difficult position. With little hope for compensation from manufacturers, they depend on potential goodwill gestures.

ADAC urges manufacturers to consider the requirements of technical inspections from the outset when designing exhaust cleaning systems. These systems should meet both homologation standards and the criteria for technical inspections. The automobile club also advocates for manufacturers to share costs and extend goodwill gestures when nearly new cars fail their first inspection due to emissions issues.

Related content