Guests drive a Jeep Wrangler Rubicon on a simulated off-road course at the Chicago Auto Show on February 8, 2018 in Chicago.

Fiat Chrysler said it sold 27,829 Wranglers in March, a 70 percent increase over the year previous. That was more than any other Jeep model, including the Cherokee, which sold 23,764 units, a 63 percent increase over last year.

But Jeep is selling a record number of the new Wranglers, as U.S. car buyers show ever greater favor for trucks and sport utility vehicles.

The Jeep Wrangler is a rugged SUV that bears a resemblance to military vehicles and has historically been meant for enthusiasts interested in plowing through giant mud puddles and crawling up boulders.

Jeep sales overall set a new record, rising 45 percent to 98,382 vehicles.

Being entirely an SUV brand makes Jeep well-suited to a changing market.

"Jeep has had a phenomenal month," said Jeff Schuster, senior vice president of forecasting at LMC Automotive, which tracks the industry. "It is really well aligned with the market, in part because of the heavy focus on SUVs in the market. That is what they do."

Jeep updated the Wrangler for the 2018 model year to offer more of the comforts not historically seen on older, more spartan Wranglers. It still offers key off-road features, such as a roll cage and locking differentials, but the newest version comes with features such as push-button ignition and Chrysler's fourth-generation Uconnect infotainment system.

It is likely that a great many of the people buying Wranglers are not taking them off-road at all, Schuster said. Part of the appeal is the design and styling of the vehicle.

"I would say a high proportion of Wranglers never see dirt," he said.