Following its experience with Ford Motor Company’s 2013 C-Max hybrid car, the EPA announced that it intends to propose revised regulations to ensure that its fuel economy labels more accurately reflect on-road performance.  The Agency said it will move away from providing single miles per gallon (mpg) values for families of vehicles and adopt procedures for rating single vehicles. 

Originally, the EPA estimated that the C-Max would achieve 47 mpg in each of three categories–city, highway, and combined.  However, following complaints from vehicle owners, the Agency retested the model and arrived at estimates of 45 mpg city, 40 mpg highway, and 43 combined–“significant” differences, according to the EPA. 

Similar but not the same

Ford based its 2013 C-Max label on tests performed on the related Ford Fusion hybrid, which has the same engine, transmission, and test weight. This approach is acceptable under EPA’s rules; the labeling regulations allow vehicles with those same three specifications to use the same fuel economy label value data since historically, such vehicle families achieve nearly identical fuel economy performance. 

For the vast majority of vehicles this approach would have yielded an appropriate label value for the car,” states the EPA.  “Conventional vehicles often share the same engine and transmission across multiple products, but are far less sensitive to the variations among these products and hence have nearly identical fuel efficiency.  But these new vehicles are more sensitive to small design differences than conventional vehicles because advanced highly efficient vehicles use so little fuel.”  In this case, the aerodynamics of the C-Max resulted in the lower fuel economy values. 

The problem appears to have emerged only in 2013, the first year manufacturers began to market families of hybrids.  The Ford hybrid family is one of only two examples in the industry where advanced technology vehicles with the same engine, transmission, and hybrid components are used across multiple vehicle designs.  EPA regulations allow, but do not require, automakers to generate a label for each design in this circumstance.

“Goodwill payments”

In light of the new values, Ford announced that it is changing the way it generates the mpg label for the C-Max and will voluntarily relabel the 2013 vehicle.  Testing to generate a label for the 2014 C-Max is not complete, says Ford. 

The company added that it is making “goodwill” payments to current C-Max owners for the estimated average fuel cost of the difference between the two labels for the 2013 model.  A customer who purchased the vehicle will receive $550, and a customer who leased the vehicle will receive $325.

Click here for information on EPA’s revised mpg values for the C-Max label.