The Jeep Wrangler is many things. Off-roader. Family car. Open-air plaything. Icon. One thing it never has been, though: fuel efficient. Blocky designs, heavy bodies, all-terrain tires and short gearing may all be part of the Wrangler’s package, but they aren’t great for gas mileage. The fact that Jeep has traditionally outfitted recent Wranglers with anemic, ancient naturally aspirated V6s that have to work overtime in real-world driving only makes things worse.In recent years, Jeep has tried to bolster