To be frank, we were a bit skeptical when the idea of a hybrid powertrain Jeep Wrangler was first mentioned. We all know that these Jeeps excel when and where the pavement ends, so the idea of adding any of this electric motor wizardry into an old-school 4×4 that’s built to drag through mud and over boulders sounds a bit out of place. Taking a step back from the hypotheticals, where the evolution of a hybrid powertrain Jeep starts to make sense is in the real world. Fact of the matter is, most Jeeps sold today spend most of their time on pavement, both in urban centres and more rural areas. While Jeep has come a long way in improving fuel economy on the Wranglers, even the most fuel-efficient model is going to burn a good two or more litres per 100 kilometres than your average sedan or crossover.
This is exactly where hybrid tech comes into play. A standard-issue gasoline-powered Wrangler Unlimited Rubicon’s reported combined fuel economy comes in at 10.2L/100km, which is about the same as the city consumption rating for a V8 Mustang Bullitt. In contrast, the Jeep Wrangler Unlimited Rubicon 4xe’s combined rating is 4.8Le/100km — a number that’s 0.1L greater than the combined economy of an all-wheel drive Toyota Prius. Do we have your attention yet? Now, to clarify, that fuel economy calculation is a bit different than what one might expect. To calculate Le, or litre equivalent, it’s not so simple as running a hybrid through a full tank and charge to see what the range works out to. Instead, a litre equivalent is a calculated value for the equivalent energy of one litre of gasoline. One litre of gasoline contains the energy equivalent to 8.9 kWh of electricity, and thus the battery energy consumption rate is converted based on this comparator. No matter how you slice it, that’s a big jump in efficiency, without any of the old “range anxiety” that some drivers still struggle with when pondering the move to an electrified ride.
How the Jeep Wrangler 4xe Powertrain Works
As you may have noticed by now, there are a few different methods that automakers are using to build electric and hybrid powertrains. In the case of many performance focused cars, motors are mounted into front and rear axles to provide electric power. Being a Jeep, this method would come with fairly significant risk, as it adds more components in reach of rocks, stumps, and other off-road hazards. Instead, the pair of motors fitted to the Jeep Wrangler Unlimited Rubicon 4xe are positioned within the confines of its engine and transmission, meaning that if an over-eager driver manages to cripple an EV motor when out on the trail, he’ll already have much bigger problems that would be there regardless of whether or not this was a hybrid vehicle.
The 4xe’s powertrain includes a pair of electric motors. The first acts in the place of the automatic transmission’s torque converter, providing a power boost between the 2.0-litre turbocharged engine and its gearbox. The second, and to many the most interesting, is a large alternator-like unit attached to a belt drive at the front of its internal combustion engine. When providing power, it spools up electrically to assist the engine itself. When the driver is off throttle, it uses this momentum to capture energy and feed it back into its onboard battery. It’s a clever yet rather simple design, not to mention one that’s designed with serviceability in mind.
Same Old Jeep, Mostly
From behind the wheel, the Jeep Wrangler Unlimited Rubicon 4xe is all we’ve come to expect from the iconic platform over the years. The upright command driving position, the simple and intuitive control layout for climate and infotainment, the electronic sway bar disconnect, the controls for locking front and rear axles; effectively all the things that make Jeep lovers as loyal as they are remain firmly in place. As with all Wrangler models since 2007, the removable hardtop is fitted with what Jeep likes to call “Freedom Panels”, which allow owners to remove the front section of the top without stripping off the entire roof.
The only place where things really change from behind the wheel of the 4xe is how it all sounds. Moving down to a four cylinder engine rather than the more common V6 does lead to a bit of what I tend to call “wrong sounding Muppets” syndrome. Not to say that the engine noise from any Jeep is the kind of thing that dreams are made of, but much like the arrival of the four cylinder Mustang years ago, when you hear this Jeep for the first time there will be moments of tilting your head in confusion. You’ll also notice a fair bit of surprise when navigating around in the jeep with the gasoline engine turned off — seems your average urbanite does not expect to see a battery powered Jeep Wrangler.
Where it really counts, noise aside, is that this new model is capable of seamless transition between power supplies. There’s little in the way of shimmy or disruption of any kind as it comes on and off of EV power, and that’s really what matters here. Simply put, Jeep hit all the right notes in building the 4xe, and while it might not convert the “Jeep purists” out there, the fuel savings alone are enough to get more of the mass market on board with the new eco-Wrangler.