A new 8-speed automatic replaces the five-speed on all trim levels, helping the standard V-6 deliver 25 mpg highway, a 2-mpg improvement. Even better is a 3.0-liter diesel V-6 with more than 400 pound-feet of torque and an estimated 30-mpg highway rating for two-wheel-drive models, which tops most of the smaller Compass models (the four-wheel-drive reaches 28 mpg). Together with its massive fuel tank, the Grand Cherokee diesel can travel 730 miles without a fill-up, according to Chrysler, which expects this model to account for 15 percent of all Grand Cherokee sales. There's no doubt this is a superior choice over the thirsty V-8, especially as all of Jeep's German competitors offer a diesel.

On select models with the adjustable air suspension, a new "Eco" driving mode lowers the SUV's ride height, tunes the engine to shut down its cylinders more aggressively and performs a few tricks with the fuel delivery system to eke out more miles.

Inside, Chrysler's latest Uconnect touchscreen infotainment system is larger, clearer, and easier to use than the current setup. A restyled instrument panel with a large center LCD display, a new shifter, softer leather on the seats and dash, and matte-finish wood graced the Overland Summit we saw.

"Every time we [do] a new Jeep, we have to make sure it's a little more capable, a little more luxurious," said Jim Morrison, Jeep's marketing director.

It'll be a few more months before you'll see one at your local dealer. We're still in shock that any full-size Jeep can claim 30 mpg. Are the planets aligning without us knowing?