by Dan Edmunds, Director of Vehicle Testing on January 15, 2016
A 2012 Jeep Wrangler Sport once lived in the Edmunds long-term test fleet. It still does, in a way, because I bought it for my very own. And I'm still tinkering with it, which is still relevant here because a 2016 Jeep Wrangler is essentially the same machine.
My main beef with the stripped-down Sport we bought has always been its lame 3.21-to-1 axle gearing, an overly-tall ratio meant to maximize the Wrangler's window sticker fuel economy at the expense of off-road performance. Back in 2012, a mere $50 would have netted us a 3.73-to-1 axle gear option that would have rectified that, but we didn't bite (note: the same 3.73-to-1 option now costs $695 on a 2016 Wrangler Sport, but that's a story for another post.)
The long-leggedness of the 3.21 gears was less than optimal in certain situations with the factory 29-inch tires they came with, but it became downright intolerable after we fitted taller 33-inch BFGoodrich off-road tires. And this was no longer just an off-road shortcoming.
June 3, 2013
After an extended long-term test it was finally time to say good-bye to our 2012 Jeep Wrangler. May was its last month on the books. April saw its last hurrah as far as mileage accumulation was concerned. Most of the past month was spent parked with a "for sale" sign in the window. All lifetime fuel economy vitals are noted below.
April 9, 2013
By now our 2012 Jeep Wrangler Sport's fuel economy has become fairly stable. Some 31,000 miles will do that to MPG data.
It's fuel economy hasn't quite lived up to EPA estimates, but tall, wide and sticky 285/70R17 BFGoodrich Mud Terrain T/A KM2 tires have not done on-road gearing, inertia or rolling resistance any favors for the last 25,000 miles. And then there's the 3-inch lift kit and the extra aerodynamic turbulence and increased frontal area it brings to the party.
March 5, 2013
One of the more specialized vehicles in our long-term fleet, the 2012 Jeep Wrangler doesn't always get out as much as the more comfortable commuters.
Even with an additional 1,000 miles added to its odo in February, the Wrangler's monthly fuel economy averages remain unchanged.
February 21, 2013
Given our Wrangler's huge tires there's no need to ever use sixth gear. At 70 mph in sixth the Pentastar V6 is turning over only about 1,850 revolutions per minute. And that's just not enough to pull even the slightest hill. Even a medium crosswind will trigger the need for a downshift. Fifth gear is only turning about 2,350 rpm at the same speed and that's a usable engine speed.
February 4, 2013
During the month of December we drove our 2012 Jeep Wrangler 1,524 miles, many of which were off road. During those four weeks the Wrangler averaged 15.9 miles per gallon of 87 octane fuel.
March 29, 2012
Once you clear Tejon pass, the run up California's Interstate 5 between LA and San Francisco is mostly straight and entirely dull. You pretty much head north and set the cruise, then settle in and pass the time while the odometer rolls up and the fuel gauge sinks down.
Most such gauges are hopelessly non-linear. The majority of cars I've owned seemed to stay bolted near "F" for the first hunderd miles and then plummet before hanging out near E for awhile. Not so in our 2012 Jeep Wrangler.
Here I'm at the half-tank mark -- it may look a shade low but the needle is actually dead-nuts on the line with my eye square with the gauge. At this point the trip meter and distance to empty (DTE) meter read more or less the same. The number of miles I've come equaled the number of miles I could still go, which is what every geeky engineer like me wants to see when the gauge reads half full (or half empty.)
It gets better. Said linerarity (or accuracy, or truthfulness -- whatever you want to call it) was still in play at a quarter tank. 79 miles is exactly one fourth of the total you get when you add DTE to the trip odometer reading.
The low fuel warning came on at 1/8th of a tank, and those numbers worked out, too.
Of course it did help that I spent the entire tank on cruise control over flat ground. Big throttle fluctuations or changes in engine load, had I made them, would have caused the DTE number to dance around and perhaps plummet as the computer re-evaluated my driving and delivered a more pessimistic prediction that would have screwed up my perfect ratios.
Dan Edmunds, Director of Vehicle Testing @ 11,777 miles
February 24, 2012
Tachometers have had red zones forever, but our Wrangler also has a green zone. As you can see, the green zone is nestled on the other side of the spectrum from the red zone. Looks to be from around 1,000 rpm up to 2,500 rpm.
It's a nice gesture and all I guess, but in all practical terms it's utterly useless.
For one, 1,000-2,500 rpm isn't exactly this engine's -- or any engine's -- sweet spot, so good luck trying to keep in the green zone. Second, do we really need a green zone to tell us that we'll get better mileage by running the engine at just over idle? I would hope not.
Ed Hellwig, Editor, Edmunds
December 30, 2011
After a few weeks with BFG mudders, our 2012 Jeep Wrangler is returning the sort of fuel economy you might expect. We averaged 17.5 mpg on stock wheels and tires for the first 5,000 miles of the test. Upgrading to the 17-inch rims and 33-inch tires has us averaging 15.6 mpg. Down about 2 mpg.
We don't have a large sample size to work with yet. This mileage calculation includes just over 300 miles and 3 fill-ups with the new setup. But it gives an idea as to the fuel economy outlook at this stage in the modification process.
Mike Schmidt, Vehicle Testing Manager @ 6,559 miles