The variability of on-road fuel economy is greater for hybrids than for conventional vehicles. Relatively small differences in driver behavior and driving conditions can have a significant effect on the degree to which a hybrid's gasoline engine is used for propulsion, which affects fuel efficiency.Changes to C-MAX Hybrid fuel economy labeling process In addition to improving the vehicle itself, Ford is changing the way it generates the miles-per-gallon label for C-MAX Hybrid going forward. Previously – and consistent with EPA's General Label rules – testing of the Fusion Hybrid was used to generate fuel economy labels for a family of vehicles, including both Fusion Hybrid and C-MAX Hybrid. The result was the same fuel economy label values for both vehicles. While the company could continue to use EPA's General Label for C-MAX Hybrid, Ford voluntarily has decided to test and label C-MAX Hybrid separately going forward. The result will be a lower miles-per-gallon label for the 2013 C-MAX Hybrid. Testing to generate a label for the 2014 C-MAX Hybrid is not yet complete. The revised 2013 Ford C-MAX Hybrid label will carry a class-leading EPA combined fuel economy value of 43 mpg – topping the combined label value of 42 mpg for the Toyota Prius v. Because this voluntary step results in miles-per-gallon values different from the original C-MAX Hybrid label, Ford also is making a goodwill payment to current C-MAX Hybrid owners for the estimated average fuel cost of the difference between the two labels. Customers who purchased their vehicle will receive a check from Ford for $550. Customers who leased their vehicle will receive a check for $325. Existing customers will be notified by mail, and Ford is working with dealers to re-label vehicles on dealer lots. Customers with questions can contact the Ford Customer Relationship Center at http://corporate.ford.com/owner-services/customer-support/contact-ford, or +1-800-392-3673. Strong C-MAX customer reaction Customer response to Ford C-MAX is strong. In fact, C-MAX Hybrid and C-MAX Energi plug-in hybrid are driving record U.S. electrified vehicle sales. Ford sold 53,014 electrified vehicles through July – 392 percent higher than a year ago. Two-thirds of buyers are coming from imports.