Nissan’s U.S.-built all-electric Nissan Leaf had been tested for efficiency a few months ago, and the numbers have now been released – with a curve ball in the form of new EPA test methodology.

The 2013 Leaf is officially rated by the U.S. Environmental Protection Agency (EPA) at 115 miles per gallon equivalent (MPGe) combined, a significant increase over the 99 MPGe for the 2012 model. The 2013’s city MPGe also spiked 23 MPGe higher than the 2012 model’s 106 MPGe, and 10 MPGe higher than the 2012’s 92 MPGe (see EPA comparison chart below).

Based on testing with a “90-percent” full battery charge, it’s EPA certified with 75 miles range displayed prominently on the window sticker, or “Monroney label.” This looks like only a smidgeon of an improvement over the 73 miles range the EPA estimated for the 2012 which it tested with a 100-percent battery charge.

Equally true is the EPA testing indicates the 2013 Leaf can travel an estimated 66 miles on a single charge if it starts out with its battery 80-percent-full, and up to 83 miles with 100-percent full battery.

In our tour of Nissan’s newly operational U.S. battery factory, we were told by the plant’s boss, Jeff Deaton, Li-Ion chemistry changes are only minor between the 24-kwh battery specified in both the 2012 and 2013 models. Others at Nissan said engineers had found efficiency gains over the 2012 Leaf’s 99 MPGe and 73 miles range, and these are responsible for this year’s improvements.

Nissan did not issue a press release in part because the displayed 75 vs 73 MPGe does not appear like much of an improvement to the uninitiated. As mentioned, the MPGe only squeaked up a tad because last year the vehicle had been range tested with a 100-percent full battery, and the 2013 was tested with a 90-percent full state of charge.

In short, it was not “apples to apples,” according to Nissan’s Corporate Communications Director, Travis Parman.

Explaining further, Brian Brockman, senior manager, Nissan Corporate Communications, outlined changes to this year’s EPA test protocol compared to 2012.

New Efficiencies & New EPA Protocol

The changes this year, wrote Brockman in an e-mail, see the 2013 Leaf’s range actually improve 14 percent over the 2012 Leaf to 83 miles under the test procedures to which the 2012 had been subjected.

And as a side-note before we go on, it should be mentioned EPA estimates are only that, estimates. Even 2012 Nissan Leafs carefully driven have seen 80-90-plus miles traveled on a full charge, thus exceeding the official 73 miles. Conversely, depending on driving conditions, the number can be less, but we digress.

For this year’s Leaf, Brockman credits the improvement in official numbers to enhancements to the 2013 Leaf’s regenerative braking system, reduction in vehicle weight and aerodynamics.

Sample 2013 Leaf Monroney label. Click on image to see it enlarged.

Sample 2013 Leaf Monroney label. Click on image to see it enlarged.

It was not Nissan’s choice to list the new model’s range estimate based on a 90-percent charge, but rather, this average was stipulated by the EPA.

“For 2013, the EPA elected to use an average of Leaf’s two charging modes to generate the range calculation for the window label an 80 percent ‘Long Life Battery Mode’ and a 100 percent ‘Long Distance Mode.’” wrote Brockman. “In the past, the Monroney label displayed range based only on a fully charged battery.”

The 75 miles based on a “90-percent charge” is thus a mid-point between the Leaf’s two default charge modes of 80 or 100-percent.

This, wrote Brockman, effectively means not only is it difficult to compare the 2013 Leaf to previous Leafs, it also muddies the comparison between 2013 Leafs and other electric cars measured under the old methodology.

Brockman added that customers who utilize the Long Life Mode on the 2013 Leaf should know that the EPA testing methodology resulted in an estimated range of approximately 66 miles.

“It is Nissan’s experience that many customers elect to use the vehicle’s default Long Distance Mode charge setting and charge their vehicle to 100 percent for maximum range. Nissan’s new battery capacity warranty (~70 percent range covered for 5 years/60,000 miles, whichever comes first) provides peace of mind to do so,” wrote Brockman. “Another indication of the improvements to the 2013 model is the increase in MPGe rating for the car. The Monroney label now shows an MPGe rating for the 2013 LEAF as 129 City / 102 Highway / 115 combined. That is an improvement from 2012’s 106 City / 92 Highway / 99 Combined.”

As a final note, Brockman said the “fun-to-drive, eco-conscious and affordable package that is the world’s best-selling electric vehicle” also meets the needs of the average U.S. driver.

Studies show 29 miles per day is typical, so even at 80-percent charge, and with 66 miles range at that setting, the Leaf can do the job.

Prior to this news being made public, Nissan’s sales already have been picking up with its best sales month since its 2010 launch being in March, followed by a second-best month in April.

The EV was also a “Top Safety Pick” by the Insurance Institute of Highway Safety (IIHS) and more and more people are catching on to what the car can do.

This is not hype either. To date, many indicators are there remains a significant proportion of Americans who do not know the Leaf is all electric, it starts at $28,800, is also eligible for subsidies, and can pencil out.

At the same time, there remains resistance and push back against electric vehicles, but today’s news only adds to the positive balance Nissan is using to chip away a greater market share, with plans for more Nissan and Infiniti EVs to come.