According to the latest publications, Germany’s transport ministry is going to assess a Porsche SUV model after reports it could be violating a diesel emissions limits.

Tests were held by the magazine Der Spiegel of the Cayenne V6 TDI and it was established that its emissions were more than permissible limits.

Porsche in the meantime has called the Spiegel test very doubtful and said that its vehicles fulfill emissions necessities.

Porsche’s sister company Volkswagen is due to pay hefty fines and costs after admitting cheating on emissions tests in 2015. Volkswagen reportedly used some of its diesel cars with “defeat device” software intended to sense testing and change performance to perk up results.

Furthermore Der Spiegel revealed that the Porsche Cayenne had a “warm up mode” with a major job to act in accordance with emissions requirements. Magazine reported that tests demonstrated that once the car was confronted with small bends or a slope it moved to a special mode and emissions were higher.

In response Porsche revealed in a statement that it had obtained information of Der Spiegel’s test, carried out with technical assessment firm TÜV Nord, but found them not credible.

Moreover Porsche reportedly noted that emissions depend on conditions such as engine load, speed and temperature.

German carmaker also said it had carried out tests on a similar Cayenne V6 TDI following the Der Spiegel statement and establish the vehicle to meet the terms with nitric oxide emission limits.

Porsche also said in a statement that it also offered to carry out joint tests with Der Spiegel but the magazine had denied the offer.