Toyota’s May tally of 243,236 sales was the automaker’s highest monthly result in six years in the U.S. and up 12.6% from year-ago on a daily-selling-rate basis, WardsAuto data shows.

Toyota sold 257,404 vehicles in May 2008, an any-month record.

“May was just one of those months where everything came together for the industry,” Bill Fay, group vice president-Toyota Div., tells media today during a conference call, citing the five weekends in the month and rising consumer confidence as motivators.

Not surprisingly, Toyota’s highest-volume models drove the automaker’s gains. But unique in recent months, cars outsold the brand’s light-truck offerings.

The Corolla saw its biggest increase yet since the 11th generation went on sale in September, up 27.0% to 36,611 units, while sales of the non-hybrid Camry rose 22.3%, to 44,385.

Counting Camry Hybrid’s 5,199 deliveries, May 2014 was the biggest month for the Toyota midsize car since August 2009, when 54,396 were sold.

Posting the largest year-on-year increase was one of Toyota’s lowest-volume cars, the Prius plug-in hybrid electric vehicle, up 282.3% with 2,692 sold. Fay says dealers in select markets are pushing the model, and Toyota hopes to move 13,000-14,000 units in 2014.

In the red were the Prius liftback and V wagon models, whose sales combined slumped 1.4% in May.

However, a good month for Prius C sales gave the entire Prius family its best-ever May. California sales largely fueled the uptick, with one of every three Toyota cars delivered in the Golden State last month a Prius, Fay says.

Posting the biggest increase among Toyota light trucks was another green model, the RAV4 EV, up 70.8% on a scant 149 sold.

The non-EV RAV4 was Toyota’s top-selling light truck by volume, with 23,316 delivered in May, up 8.5% on a DSR basis from year-ago.

Other Toyota light trucks in the black included the 4Runner SUV (up 63.6%); Sienna minivan (up 8.4%); Tundra fullsize pickup (up 10.2%); and the gasoline-engine-only Highlander CUV (up 6.6%).

Lexus sales rose 16.6% on a DSR basis in May to 26,921 units, although about half of its nameplates slipped below May 2013.

The ES 350 again was the luxury brand’s top-selling car, with 5,115 sold, up 10.5%.

The CT 200h hybrid hatchback is revitalized after a refresh and sales rose 4.5%, but the ES 300 hybrid slipped 5.5% and the GS hybrid plunged 77.8% from year-ago.

A year after its current generation was launched, the IS lineup posted a whopping 123.6% increase, but trailed the ES 350’s tally by roughly 700 units.

The non-hybrid GS and LS large sedans also slumped in May, as did the LX SUV and RX hybrid CUV.

The non-hybrid RX 350 increased sales 6.3% from last May on a DSR basis; a refresh continues to bolster GX SUV sales, which grew 153.1% last month vs. year-ago.

Scion still is struggling with its current range of offerings, falling 9.6% from May 2013.

As has been the case in recent months, the tC coupe was the only positive seller for the brand, rising 17.4% in May.

All other Scion models slipped below year-ago, including the closely watched FR-S sports car, which had the second-highest volume among Scions in May but fell 17.3% short of like-2013.

Both Fay and Jeff Bracken, Lexus group vice president, foresee a sunny summer for their respective brands, although both are suffering through some inventory shortages.

Toyota is shy of Highlander, Corolla, Tacoma and RAV4 units, largely due to a continuing rail-car shortage. Fay estimates the industry has 100,000 vehicles waiting to be shipped by rail, with 15,000 of those Toyotas.

Bracken says Lexus’ shortage has more to do with the fast pace of sales for the brand, with dealers selling vehicles faster than Lexus can ship them.

However, both executives expect inventory woes to alleviate in the month of June.

Fay says incentives will be modified from May, when Toyota had a national marketing campaign, but only slightly as Toyota wants a “good, strong car summer.”

cschweinsberg@wardsauto.com