With the current JK series Jeep Wrangler due for replacement after a decade of service, the automaker is working on making the next-generation version of its iconic model more fuel efficient than ever. But those updates won't be at the expense of its heritage or off-road prowess, Automotive News reports.

"Don't screw it up," was the guidance Jeep's Mike Manley told the team behind the next-generation Wrangler, according to the report. Manley's words apply not only to the model's off-road capabilities, but its signature styling as well.

"We're obviously hoping to continue the success of the next-generation Wrangler," Manley told Automotive News. "We've pushed this vehicle forward in many areas -- fuel economy being one of them and that's going to help us in many of the international markets."

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While the next-generation Jeep Wrangler will feature new lightweight materials, revised aerodynamics, and more efficient drivetrains in an effort to increase fuel economy, it will ride on an all-new lighter and stronger frame as well as retain its solid front and rear axles. And don't expect its styling to stray too far from its boxy shape.

That stronger and lighter frame will be surrounded by several new aluminum body panels in place of the current model's steel bits. The front grille and windshield on the next-gen Wrangler are also said to feature a "steeper rake" than the current model.

"You have to be very careful with the aero of Wrangler, because at the end of the day, it needs to be recognizable as a Wrangler. To some extent that restricts you on some of the aero that you can do. But with weight and a number of the changes that we've made, you're going to see that we've really pushed that vehicle forward in terms of its fuel economy."