From the Associated Press — Ford says it has launched an investigation into whether a flawed mathematical model caused it to overstate gas mileage and understate pollution from a wide range of vehicles. The company says a group of employees reported possible problems with the model in September. It has hired an outside firm to test the 2019 Ford Ranger. If problems are found, then Ford will start looking at models going back to 2017. Ford says it has no evidence yet that mileage or pollution numbers are wrong, but the investigation has just started. The company says it’s too early to tell how many and which models might be involved. The U.S. Environmental Protection Agency and California regulators have been informed about the situation, according to the automaker.