Consumers snapped up everything from trucks and SUVs to performance vehicles as dealers finished the month with a strong showing over the Memorial Day weekend.
Jessica Caldwell, Edmunds' director of industry analysis, said buyers are getting more car for the money.
"Car buyers continue to pay more for vehicles and mitigate that cost with longer loan terms and low interest rates," Caldwell said. "Average new vehicle loan terms continue to inch up. The average new vehicle loan term was 67.9 months in May, the highest ever. The average new vehicle loan APR fell to 4.6 percent in May from 4.8 percent in April. With available longer loan terms, lower interest rates and abundant lease deals, people really are getting get more car for the money."
Volkswagen reported an 8-percent sales increase compared to May 2014. The Golf family of cars turned in the best May since 2000. VW delivered 410 2015 e-Golfs, the best month ever for the electric hatchback.
"Demand for the all-new Colorado midsize pickup is rising faster than GM's ability to increase production, even with the addition of a third production shift in March," the automaker said in a statement.
The Equinox was up 30 percent compared to a year ago and the Traverse rose 2 percent.
Fiat-Chrysler sales rose 4 percent compared with May 2014, as the automaker extended its streak of year-over-year sales gains to 62 consecutive months.
Mustang turned in its best May and year-to-date sales results since 2007 with 13,616 cars sold. Southern California is now a hotbed for Mustang sales, according to Ford.
"We continue to see strong consumer demand for our newest products, including Edge, F-150, Mustang, Transit vans and Lincoln MKC," said Mark LaNeve, Ford vice president of U.S. marketing, sales and service, in a statement. "Our all-new F-150 is still turning on dealer lots in 26 days against tight supply, and F-150 average transaction prices set a record in May as consumers continued buying a rich mix of high-series pickups."
Nissan announced total U.S. sales for May of 134,779 units for a decrease of 0.8 percent.
Toyota sales were flat, according to a preliminary report from the automaker.
"The new Honda HR-V hit the ground running with an incredible sales performance in just a half month on the market with the all-new 2016 Pilot coming to market this month to further accelerate light truck sales," said Jeff Conrad, Honda Division senior vice president and general manager, in a statement. "Despite the market trend toward light truck sales, our trio of Fit-Civic-Accord remains popular with individual buyers, and we're looking forward to a summer of hot sales."
Edmunds says: Dealers are riding the crest of some significant momentum as we head into the summer selling season.