Automakers released U.S. June sales figures on Wednesday, and it was Nissan leading the way with a more than 13 percent increase in sales over last year as crossover SUVs remain the momentum theme in the industry.

Fiat Chrysler U.S. June auto sales rose 8 percent from a year ago, boosted by the continued strength of its Jeep SUV brand, while Toyota and Ford Motor's trailed behind—seeing U.S. auto sales jump 4 and 2 percent, respectively. Separately, GM's June sales slipped 3 percent despite the best June on record for its Chevrolet crossovers.