The Blue Oval is currently looking into why incorrect calculations were made when formulating fuel economy and emissions figures to the EPA in the US. There's no fear of defeat devices, though.

Ford Motor Company could be in hot water regarding emissions and fuel consumption data, after the company's employees raised concerns incorrect figures were submitted to regulators and consumers.

A new report by industry journal Automotive News Europe says the Blue Oval has recently hired external investigators to figure out whether its internal processes translated to inaccurate data.

Ford's vice president for sustainability, environment and safety engineering, Kimberly Pittel, told Reuters last week the investigation does not involve the use of defeat devices, however.

"We have voluntarily shared this information [with the EPA and California Air Resources Board]," Pittel said.

"We are going to go where the investigation takes us."

The EPA said in a statement it cannot come to any conclusions at this early stage.

"We take the potential issues seriously and are following up with the company to fully understand the circumstances behind this disclosure," the emissions body added.

The first vehicle to be investigated is the US-market 2019 Ranger pick-up, with the company expecting results and data to be confirmed next week – it's worth noting the Ranger is only available with petrol engines Stateside.

PIttel said it isn't clear how the review will impact current advertised mileage or fuel economy data that has been submitted to regulators, nor how many Ford vehicles the review could effect if the data needs to be revised.

Several environmental groups have slammed the manufacturer following news of the investigations.

"It’s shameful that Ford waited months to disclose issues with its emissions testing," said the Sierra Club, Public Citizen and Safe Climate Campaign in a joint statement.

"These actions are only magnified by the company’s attempts to undo and weaken the current emissions standards."

"After repeated cheating scandals and failure to comply with clean air safeguards, the auto industry has proven that it cannot be trusted to act in the public’s interest. We need common-sense standards and an EPA Administrator who will put the public and their safety first, not polluter profits," they continued.

It's not the first time Ford has had to revise its official fuel consumption figures, either. Back in 2013 the company was forced to cut 7mpg off the official fuel economy for its C-Max hybrid variant following complaints about the real-world mileage.

A similar move was made a year later across six other models, with Ford lowering economy ratings and offering compensation to customers.