The all-new 2014 Jeep Grand Cherokee SRT is a monster. If you peek through the functional cooling nostrils atop the lightweight hood, there's a massive 6.4-liter Hemi V-8 engine that's ready to unleash all 470 horsepower. Amid the changes and upgrades for the new model year, there's an Eco mode and an eight-speed automatic transmission. The 2014's EPA-estimated 19 mpg highway rating is an improvement over the 2013 model's 18 mpg.
Does the 2014 Grand Cherokee SRT get that highway number in the real world with all that Hemi power?
To find out, I took it home for five days and put it through all sorts of driving scenarios including a 180-mile road trip from Door County, Wis., to Milwaukee.
Eco mode didn't make a noticeable difference in gas mileage, and it was a much more enjoyable, smoother driving experience with it off. On two of the highway driving sprints with similar traffic patterns, observed gas mileage was nearly identical, even with the Eco mode turned off. I also tracked three legs of city driving, using Eco mode again proved to make little difference in the Jeep's around-town fuel economy. The more interesting finding was that I beat the EPA-estimated city rating of 13 mpg, even managing 17 mpg for brief stints. Even on the highway, I was besting the EPA rating for a majority of the time.
My advice is to avoid Eco mode and let the "Super Jeep" roar on.