Nissan’s rollout of its Leaf electric vehicle in the U.S. has yet to accelerate, causing frustration for customers as well as company executives due to production constraints in Japan where the car is built.

However, Japanese buyers appear to have the edge.

Nissan sold 87 Leafs in the U.S. in January, following 19 deliveries in December, the month the car went on sale here, Ward’s data shows. But a Japanese website reports the auto maker had delivered a total 981 leafs in the domestic market by the end of January.

A spokeswoman for Nissan North America is unable to confirm that figure.

The higher delivery volume in Japan reportedly is due to a government incentive that expires at the end of March.

To date, Leaf sales in the U.S. are trailing the Chevrolet Volt extended-range EV, which launched in November. General Motors delivered a total 647 Volts through January, Ward’s data shows. The EREV only is available in the U.S.

Nissan has said it is taking its time building the early production units to avoid quality issues. However, a company official recently was quoted as saying output will ramp up in late March.

The frustration U.S. Leaf buyers have expressed to Nissan over the slow delivery of their car is matched by U.S. executives, who say customers expectations are unrealistic.

“How do you deliver 20,000 cars in one month?” Brian Carolin, NNA senior vice president-sales, told Ward’s last month. The Leaf currently is offered in California, Tennessee, Oregon, Washington and Arizona, Texas and Hawaii.

NNA spokeswoman Katherine Zachary says media reports that Nissan has converted only 8,000 of the 20,000 reservations into orders are misleading, noting some people who reserved a Leaf last year do not live in the initial launch markets or are waiting out existing leases.

Carolin said in the interview a 4-to-7 month delivery time is not out of the question, adding Carlos Tavares, chairman of the Nissan Americas region, has said all 20,000 Leafs should be in customers’ hands by the end of this summer.

The car’s reservation process, which requires interested buyers to make a $99 deposit to secure their place in line, may have created unrealistic expectations, Carlin notes.

“We had a ton of people who came much earlier than we anticipated with their $99, which I think set up a level of expectation, all of them expecting they were going to get their car in January. It doesn’t (work that way).”

The need to deliver the Leaf to the first group of reservation holders means Nissan will not reopen the reservation process until sometime in “spring,” Carolin says.

Meantime, AeroVironment, Nissan’s official charging-station supplier for the Leaf, says it has installed “thousands” of its charging stations in the U.S. at dealerships, retail stores and private homes.

Kristen Helsel, vice president-EV Solutions for AeroVironment’s Efficient Energy Systems, says many Volt buyers are opting for her company’s charging station.

The unit costs $2,000, including installation, for Leaf buyers via a deal with Nissan. VeroVironment also has begun retailing a smart version of its charging unit, which communicates with the electrical grid to determine optimal charging EV-charging times.

The smart charger is not part of the deal with Nissan, but “stay tuned,” Helsel says, adding Leaf customers in Houston and Dallas can get the new charger as part of a program with their local electric company.

cschweinsberg@wardsauto.com