Updated

Consumer Reports says Ford’s highly touted new hybrid cars are delivering lower than expected fuel efficiency.

In real world testing conducted by the magazine, the 2013 Ford Fusion Hybrid, which has an EPA rating of 47 mpg, got 39 mpg while the 2013 Ford C-Max Hybrid, also rated at 47 mpg, delivered just 37 mpg.

The publication says that these are the worst discrepancies it’s ever seen in its tests.

Several other outlets, including Green Car Reports and FoxNews.com, have also noted that the cars seem to come up short of their advertised mpg.

Official fuel economy ratings have become a hot topic in recent days after Hyundai and Kia were found by the EPA to have reported incorrect mpg figures for several of their cars due to faulty in-house testing procedures.

Read: EPA finds Hyundai, Kia overstated gas mileage

Most automakers conduct their own fuel economy tests based on rules set down by the EPA, which spot checks only about 15 percent of the new cars that come out each year. Ford has not yet said whether or not it self-certified the Fusion and C-Max Hybrids, or if they were tested by the EPA.

Even with the discrepancies, Consumer Reports notes that the Fusion returned the highest mpg of any mid-size sedan it has tested, while the C-Max hatchback was second in its class only to the Toyota Prius V.

Ford responded to the report with a statement saying, "early C-Max Hybrid and Fusion Hybrid customers praise the vehicles and report a range of fuel economy figures, including some reports above 47 mpg. This reinforces the fact that driving styles, driving conditions, and other factors can cause mileage to vary."