The Wrangler's evolutionary design will hide some pretty radical changes.

Jeep dealers already know a great deal about the next-generation Wrangler that will debut later this year at the Los Angeles Auto Show. They're not supposed to talk, but one of them broke the silence by posting everything he knows on an enthusiast forum.

All-new from the ground up, the 2018 Wrangler will again be offered as a two-door and as a four-door named Unlimited, according to JLWranglerForums. Two-door buyers won't be able to order the upmarket Sahara trim, while Unlimited owners will benefit from a longer wheelbase. A pickup truck will join the lineup later in the production run, though it won't be shown alongside the regular model in the City of Angels this year.

Jeep will pack more tech into the Wrangler, including a start-stop system, a push-button ignition, and a trick power-folding hard top. We expect to see Fiat Chrysler Automobile's latest Uconnect infotainment system, too.

The base engine will be an updated variant of the current car's 3.6-liter V6. A manual transmission will come standard, and an automatic transmission will be offered at an extra cost. A 2.0-liter turbo four will be offered at an extra cost, but it won't be available with a manual transmission.

The anonymous dealer reports Jeep will offer the Wrangler with a turbodiesel engine in the United States for the first time ever. It won't launch until late in the 2019 model year, so at least a year after the off-roader goes on sale.

We'll learn more about the next Jeep Wrangler in the weeks leading up to the Los Angeles Auto Show. It will arrive in showrooms nationwide before the end of the year.