Automotive News has a couple of spy shots showing a Wrangler test vehicle with about 10 inches added in front of the windshield. Other sources say it's about 2 inches longer.
The newspaper speculates that the extra room is required to fit an 8 speed transmission. This transmission is used in Jeep Grand Cherokee, Dodge and Chrysler cars, and Ram 1500 truck models. So just about any of FCA's V6, V8 and Diesel engines could be used.
http://www.autonews.com/article/20150928/OEM03/309289968/longer-jeep-wrangler-on-the-way
The newspaper speculates that the extra room is required to fit an 8 speed transmission. This transmission is used in Jeep Grand Cherokee, Dodge and Chrysler cars, and Ram 1500 truck models. So just about any of FCA's V6, V8 and Diesel engines could be used.
http://www.autonews.com/article/20150928/OEM03/309289968/longer-jeep-wrangler-on-the-way