When Nissan transferred the production of its Leaf electric vehicle from Japan to the United States, the carmaker was able to implement a few mid-cycle engineering changes. These changes, while maybe a few, have allowed the Japanese carmaker to improve the EPA fuel economy of the 2013 Nissan Leaf, according to spokesman Brian Brockman.
The production shift to the carmaker’s Smyrna site in Tennessee has paved way for some enhancements for the 2013 Leaf. For instance, the 2013 Leaf is now equipped with an improved regenerative braking system and contains a few areas of improved aerodynamics.
Thanks mainly to a modification in the front bumper fascia, the new Leaf now boasts of drag coefficient of 0.28, compared with the previous model’s 0.29. Nissan also implemented some component changes -- including the instalment of a smaller charging unit – that cut the Leaf’s total weight by 129 lbs.
The Japan-made 2012 Nissan Leaf registered a 99 MPGe (miles per gallon equivalent) for combined city and highway driving. On the other hand, the US-produced 2013 Nissan Leaf electric registered a 115 MPGe in combined city and highway driving.
However, Nissan claims the improved EPA figures for the 2013 Leaf are still slightly lower than they should be due to the agency’s practice of averaging the two driving modes.
Nissan and EPA have tussled over the creation of an accurate consumer comparison between gasoline-engine vehicles and battery-powered ones. Brockman remarked that the EPA has implemented a new testing methodology that made comparisons to previous models difficult. In 2012, EPA’s fuel economy test measured the Leaf's range with a 100 percent-charged battery.
This year, however, the EPA's estimates averaged two Leaf driving modes. The first mode entailed testing the car with a 100-percent battery charge. The second entailed testing the Leaf's battery-saving Long Life Battery Mode, which prevents it from being charged beyond 80 percent of its capacity. According to Brock, if the EPA only used the first mode, the 2013 Leaf would have yielded higher MPGe numbers.