Hawaii sales of cars and light trucks shot up 20.5 percent in the first quarter as an improving state economy and growing demand fueled a nearly fivefold percentage gain compared with the rest of the country.

Vehicle sales nationwide rose just 4.3 percent over the same year-over-year period, according to a Hawaii Auto Outlook report due for release Friday.

"The mainland number was somewhat affected by the rough winter weather, but that didn’t account for such a dramatic difference," said Dave Rolf, executive director of the Hawaii Automobile Dealers Association.

"That big difference likely is attributed to Hawaii’s current robust economy and the pent-up demand from previous low rates of sales," he said, adding that Hawaii’s new vehicle registration rate always trails that of the mainland. "The mainland retail auto industry showed an earlier return in auto sales."

Registrations, which reflect auto sales at the consumer level, increased to 13,218 during the January-March period compared with 10,973 in the year-earlier quarter.

In 2013, statewide registrations rose 14.7 percent to 48,766 from 42,506 in 2012. The national increase last year was 9 percent.

The 20.5 percent sales increase in Hawaii is the largest quarterly rise since a 24 percent spike in the third quarter of 2013 and is the first time the first-quarter rate has jumped so high since the first quarter of 2012, when registrations were up 21.5 percent.

Rolf said the big sales increase also means that "tax revenues going to the state from the new-car sector should be up … (which makes it) all the more puzzling that the Council on Revenues recently downgraded their estimate to 0.0 percent tax growth for fiscal year 2014."

He noted that the downgrade caused a number of funding problems during the most recent legislative session. One of those issues would have addressed the build-out of hydrogen-fueling infrastructure for the increasing manufacture of zero-emission, hydrogen-powered vehicles.

Light truck sales led the way last quarter, comprising 51.2 percent of vehicle registrations in the state; car sales encompassed 48.8 percent of the market. In 2013, sales of cars edged out light trucks 50.8 percent to 49.2 percent.

Hawaii auto sales figures have been steadily rising since the bottom dropped out of the market with 32,688 registrations in 2010 following the economic collapse.

Toyota remained the market share leader in cars and light trucks during the first quarter with the Corolla being the No. 1-selling car in Hawaii.

Subaru sales showed the highest percentage change year-to-date, up 59.1 percent through March versus the same period last year.

Toyota commanded 26.7 percent of the market during the first quarter, just a hair higher than the 26.5 percent of the market share in the first quarter of 2013.

Second and third in the market were Honda at 15.2 percent and Nissan at 10.9 percent, both showing slight gains over their sales in the year-ago period.

Sales of U.S. vehicle brands in Hawaii were up 17.4 percent from the year-earlier quarter and represented 19.3 percent of the state market.

Chevrolet sales are down a bit, likely due to recalls and the publicity stemming from them, but overall "business is very good, and our quarter is pretty much mapping what the report shows," said multidealership owner Nick Cutter.

It is not uncommon for first-quarter sales to be robust, he said, but another "big selling season, in May, June and July," also is generally strong.

"I think it’s just the economy right now is pretty darn good. It’s been on a steady climb since 2010."

Cutter credited low unemployment and an increase in construction for light trucks recapturing the lead in market share over passenger cars.

The report projects new retail registrations of cars and trucks in 2014 to now total 53,000, higher than an earlier projection of 51,000 that was based on data collected through 2013.

"I think this is a forecast of what’s going to be a few solid years," Cutter said.

However, the report points out that while sales are expected to increase, the market is approaching its cyclical peak, and that pent-up demand resulting from the economic downturn has eased.

Sales of alternative power-train vehicles, such as electric and hybrid models, comprised 6.1 percent of the first-quarter market, slightly higher than a year ago.

On a county-by-county basis, Kauai saw the largest percentage increase of vehicle sales at 32 percent. Oahu had the highest sales volume at 9,813 vehicles.