New research claims that vehicle manufacturers are “again manipulating official tests, this time on safety by adjusting indirect tyre pressure monitoring systems (TPMS) to pass the lab test but failing to perform on the road”.
The findings were published by campaigning body, Transport & Environment (T&E) after it commissioned IDIADA to test a Volkswagen Golf and a Fiat 500L equipped with indirect TPMS to perform a copy of the type approval test carried at IDIADA, which they passed.
However, out of 16 real-world tests, the Golf failed 14 and the 500L all 16.
Such indirect systems rely on tyre vibration and wheel rotations to detect low pressure, while the more effective direct TPMS have sensors to accurately measure the pressure in each wheel.
Julia Poliscanova, clean vehicles manager at T&E, said: “With Dieselgate, carmakers were caught wilfully putting the public’s health at risk from poisonous emissions.
“Now we find manufacturers could be deploying similar defeat devices to get ineffective tyre pressure monitoring systems to pass safety tests and save themselves €10.
“Our tests clearly show that the unsafe indirect systems put drivers, pedestrians and cyclists at greater risk of dangerous blow-outs.”
The T&E says the most suspicious results were obtained when the same regulatory test was repeated on tyres with some mileage; the TPMS failed to alert drivers of tyres’ low pressure.
It suggests that the indirect systems were primed to get through official tests but become less sensitive once they were used on the road.