Efforts to fill a void in midsize pickup trucks appears to be paying off for the world’s third-largest automaker. General Motors Co. said Friday its 2015 Chevrolet Colorado, which went on sale to much fanfare in September, had its best sales month yet in April, with inventory turning over at dealerships on average every 15 days.

The Colorado and its nearly identical sibling the GMC Canyon already have carved out about a 30 percent share of the U.S. small pickup truck segment, challenging the Toyota Tacoma and the Nissan Frontier. The existing line of small trucks has been stale, lacking any recent introductions until GM stepped in last year. Toyota's next-generation Tacoma isn't due out until next year, giving GM a chance to snatch market share. 

"General Motors has enjoyed continued success with its small truck lineup in April,” said Jessica Caldwell, senior auto analyst at Edmunds.com. “GM's popular truck duo enabled the small truck segment to be the quickest-selling of all segments last month. Once shunned by U.S. car buyers, small trucks are enjoying newfound popularity."

GM said its total vehicle sales increased 6 percent as buyers gravitated to its inventory of large SUVs and trucks, including the ever-popular Chevrolet Silverado.

“Consumer and commercial customer demand for pickups and utility vehicles has been building since last fall,” GM’s head of U.S. sales, Kurt McNeil, said in a statement. “The auto industry continues to be on track to have its best sales year since 2006.”

Kelley Blue Book estimates that by the time all automakers report their U.S. sales numbers, April’s seasonally adjusted annualized rate – a running 12-month measure of sales – would be 16.5 million units. This means enough cars were sold in April to hit at least 16.9 million in 2015, up from 16.8 million last year and the highest rate since 2005.

“But we might see sales hit 17 million or even higher,” said Alec Gutierrez, senior analyst at Kelley Blue Book. GM also reported big gains in SUVs, like Chevrolet’s Equinox and Traverse, which reported double-digit growth in the first four months of the year. And Cadillac sales rose 14 percent on Escalade deliveries and demand for the SRX crossover and XTS full-size sedan.