In February, Ford initiated its own investigation of emissions testing practices at the request of employees who identified inconsistencies in the results. Whistleblowers believe that Ford has miscalculated the "road load" or factors that affect a car while driving. These include air resistance and tire resistance. A laboratory test that does not take into account exactly the forces a vehicle would encounter on the road could lead to better fuel economy forecasts, suggesting that cars are less polluting than they actually are.
In addition to the internal investigation, Ford has also notified the Environmental Protection Agency and is working with the California Air Resources Board to resolve the issues. The proactive steps seem to be consistent with the fact that Ford did not purposely try to circumvent rules, but legitimately made mistakes in calculating its numbers.
Ford is not the only company currently facing an emissions investigation. Daimler, the parent company of Mercedez-Benz, and Fiat Chrysler also conduct their own criminal investigations, even though both companies are accused of using cars with defeat devices and software to make cars run cleaner than they actually are.