2018 Jeep Wrangler: Monthly Update for November 2018
by Calvin Kim, Road Test Engineer
Where Did We Drive It?
With a month filled with events, tests and holidays, our 2018 Jeep Wrangler sat idle for much of November. When we did drive it, it was mainly on the mean streets of Los Angeles rather than the dusty trail. So rather than talk about on-road steering or interior noise, we'll talk about an opportunity we had to take a two-door Jeep Wrangler Rubicon over one of the most difficult off-road trails in America, the Rubicon Trail in Truckee, California. This Jeep had a twist: It was equipped with Jeep's new powertrain.
What Kind of Fuel Economy Did It Get?
With nothing but city driving in November, we only went through three tanks of gas and covered 575 miles. Not impressive, but it happens. Unsurprisingly, the stop-and-go driving of city life took its toll on our fuel economy average, causing it to drop one-tenth of an mpg. We'll make up the miles over the holidays.
Average lifetime mpg: 17.5
EPA mpg rating: 20 combined (18 city/23 highway)
Best fill mpg: 32.7
Best range: 357.3 miles
Current odometer: 14,229 miles
Maintenance and Upkeep
Another recall! Hot off the heels of the powertrain control module recall, we just received another one. This recall involves a right-rear passenger door latch that's not installed in the correct location on 2018 JL Wranglers. Unlike the previous recall, this one is also more limited in scope, affecting only 52 Unlimited models. Fiat Chrysler will contact owners and begin recall repairs on December 28. If you'd like more information, contact Chrysler customer service at (800) 853-1403 and reference recall UB6.
On a recent trip to the notoriously tricky Rubicon Trail in Northern California, we tested the Wrangler Rubicon's new hybrid engine and off-road features.
Two well-executed features allow the Rubicon to contort its axles into all sorts of positions and yet still drive out of them. Thank the disconnectable front anti-roll bar for allowing for more front axle flex. And when the axles are flexing at different angles and the tires are gripping for any hint of traction, the lockable differentials save the day.
So what does all this stuff do? On a regular car, the driven wheels receive torque through an open differential. This type of differential typically sends power to both wheels and allows them to turn at different speeds when cornering. It works fine for most applications and, unsurprisingly, it's the standard differential in most cars.
The Jeep has two of them, one in the front and one in the rear, and each can be locked. Locking forces the wheels on a given axle to turn as one. Why would you want this? An axle with an open differential will simply spin the wheel with the least amount of grip, such as when it's in the air or on a loose surface, and you'll get nowhere. By locking the wheels together, you'll be able to continue climbing and moving forward.
On the Rubicon, you'll need to have the transfer case in 4-Lo to lock the rear differential. If you still need more traction, specifically for rock crawling or climbing the gnarliest of routes, you can lock the front differential, too.
In this configuration, you'll have horrible on-road handling, but at the speeds you'll be going, it won't matter. Instead, you'll be happy to have all four wheels clawing at the ground and moving you forward.
Of course, you should probably have the front anti-roll bar disconnected when you're on such trails as well. Usually, the front anti-roll bar aims to keep the body level when cornering, but it can limit front suspension travel when off-roading. Disconnecting the anti-roll bar increases the mobility of the front axle but reduces handling performance. In the new Jeep, if you forget to reconnect the bar, it will do it automatically once the vehicle speed exceeds 18 mph. Unlike locking the differentials, the anti-roll bar can be disconnected in either 4-Hi or 4-Lo.