In Germany, the annual roadworthiness inspection, known as the Hauptuntersuchung and overseen by the national technical inspection agency TUV, is a crucial process. Conducted on millions of vehicles each year, it determines which cars are fit for the road and which require immediate repairs.
The newly released 2026 TUV Report analyzed 9.5 million inspections carried out between July 2024 and June 2025, revealing a concerning trend: overall vehicle quality is declining. More than one in five cars—21.5 percent—failed the inspection due to significant or dangerous defects.
While reliability issues span all vehicle types and ages, electric vehicles, particularly from one brand, faced intense scrutiny. For the third consecutive year, Tesla models ranked lowest in the report, suffering the highest rates of mechanical failure. Among vehicles aged two to three years, the Tesla Model 3 displayed a 13.1 percent defect rate, meaning one in every 7.6 cars failed the safety check on the first inspection.
Even more troubling, the Tesla Model Y posted a defect rate of 17.3 percent in the same age group, marking it as the worst-ranked vehicle that TUV has recorded in this category over the last decade. Common issues identified included problems with the axle assembly, suspension, brakes, and lighting systems.
However, reliability challenges are not inherent to all electric vehicles. The data highlights that some electric models perform exceptionally well. For example, the electric Mini Cooper SE recorded a low defect rate of just 3.5 percent among two-to-three-year-old cars. Similarly, the Fiat 500e led the small car segment for nearly new vehicles, demonstrating that electric mobility does not necessarily correlate with major maintenance issues.
The report also showed a rise in minor defects, now affecting 12.3 percent of vehicles, signaling increasing mechanical difficulties for car owners across the board.
To recognize endurance, TUV introduced a Long-Term Quality award this year for vehicles aged 10 years and older with the lowest average rates of safety-related defects. Mercedes-Benz earned the top honor, with an 18.5 percent defect rate among its oldest cars. Audi followed closely with 19.2 percent, and Toyota secured third place at 22 percent. Notably, the defect rate for decade-old Mercedes vehicles is similar to that of the two-to-three-year-old Tesla Model Y.
While electric vehicles drew significant attention at the lower end of reliability rankings, several well-known gasoline and diesel models also showed considerable issues. Poor performers among older vehicles included the BMW 5-series and 6-series (in four-to-five and eight-to-nine-year age brackets), the Dacia Duster (six-to-seven and ten-to-eleven years), and the Renault Clio (12 to 13 years).
The 2026 TUV Report sends a clear message to prospective buyers and current vehicle owners alike: regardless of whether you drive a combustion engine or an electric car, component quality and maintenance are more critical than ever.
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