By 2025, the new cars and trucks each automaker sells in the United States will have to average 54.5 miles per gallon of fuel. The Jeep Wrangler now gets about 21 mpg on the highway. That’s a big gap.

But Chrysler Group Chief Executive Officer Sergio Marchionne says his company, which makes Jeeps, is already working on the next-generation Wrangler, although it remains years away. He says the redesigned Wrangler will reflect concerns for both fuel economy and keeping the Toledo Jeep plant fully operating during the transition.

The latter is a big promise. It was not possible when Chrysler replaced the Jeep Liberty with the redesigned Cherokee, and that cost both the automaker and its workers dearly.

The high-selling Wrangler is also intended for global sale. It will need to be leaner and greener for buyers and regulators abroad. Chrysler is said to be considering a diesel engine as an option.

So far this year, Chrysler has sold more than 92,132 Wranglers — an 11-percent increase from the year-ago period. Mr. Marchionne said: “I don’t ever, ever want to stop the Toledo plant from making Wranglers.” Again, that’s reassuring.

First Published August 12, 2013, 11:55 p.m.