Jeep Wrangler Unlimited 2019 rubicon (4x4)

2019 Jeep Wrangler Rubicon diesel review

Rating: 7.8
$54,760 $65,120 Dealer
  • Fuel Economy
  • Engine Power
  • CO2 Emissions
  • ANCAP Rating
To diesel, or not to diesel? That is the question for prospective Wrangler Rubicon buyers.
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For the first time, you can now opt for diesel power in your 2019 Jeep Wrangler Rubicon.

The old JK Wrangler used to be available with the VM Motori 2.8-litre diesel engine on all specifications bar the Rubicon, because of clearance issues with the flexier, heavy-duty front differential and a tall, long-stroke diesel engine.

This time, it’s gone full circle. The 3.6 litres' worth of petrol V6 is your only choice on all models, except for the Rubicon. On top of the long-serving Pentastar engine, you can now opt for a 2.2-litre, four-cylinder ‘MultiJet II’ turbo diesel donk with the full-fat off-road model. It's actually 2143 cubic centimetres of displacement, so could technically be rounded down closer to 2.1 litres.

The Wrangler's new 2.2-litre diesel delivers 147Kw @ 3500rpm and 450Nm @ 2000rpm.

It’s also the ticket into the most expensive Wrangler money can get. Prices recently got a bump upwards by a couple of grand to $70,950. That’s $5500 more than the petrol-powered Rubicon, and $17,500 more than the entry-level rag-top Unlimited Sport S.

Check out our review of the petrol-powered Wrangler Rubicon here, where we pushed it hard off-road.

The diesel motor is mounted up to the same eight-speed gearbox, with the same forward ratios (reverse is a bit shorter). Bolted to that is the same ‘Rock-Trac’ two-speed transfer case giving you a 4:1 reduction in low-range.

The differentials are the same bigger and stronger Dana units than normal Wrangler fare, for increased durability on the low-speed, high-strain, technical 4WDing. It’s worth noting a different differential ratio between the petrol and diesel Rubicons. If we are talking only spec-sheet bragging rights between the two models, then the petrol wins with a 77:1 low-range ratio. The diesel makes do with 70.2:1.

The two engines develop their power and torque in very different manners, however. Whereas the petrol needs to wind all the way up to 4100rpm for its allotment of 347Nm, the diesel makes 450Nm at 2000rpm. So, while the petrol Wrangler has better gearing, the diesel is a happier engine at the lower end of the tachometer.

This change in gearing lets the diesel Rubicon sit in that sweet spot nicely on the highway, with an eight-speed gearbox that rarely puts a foot wrong. There’s certainly less acceleration available under full throttle, and a bit more oiler-rattling going on under the bonnet, but there’s enough useful punch for most traffic scenarios.

Fuel economy for us worked out to be between 10–11L/100km depending on how much traffic you found yourself stuck in. Jeep gives the factory figure as 7.5 L/100km in mixed use.

Because of those 32-inch BFGoodrich tyres, and because of the flat windscreen and the soft, off-road-focussed suspension, there’s a definite compromise of shortcomings on the blacktop. The Wrangler tends to wander around at highway speeds, and there’s noticeable wind and road noise intruding into the cabin. This is all compared to vehicles without the hardcore underpinnings of a Wrangler, however. It’s part of the price you’ll need to pay for that intense off-road prowess.

And that's something you’ll be wanting to tap into, if you buy this vehicle. Those less appealing on-road characteristics are easier to stomach when you experience that surefooted ability off-road. The way the body sits low and flat, as the suspension does all of the hard work underneath, leaves a feeling of stability that nothing unmodified can match.

And when you combine that stability with the ultra-low gearing and grippy KM2 Mud Terrain tyres, you’re left with a package that is able to simply crawl and crawl and crawl. This Jeep feels like it will just keep driving until it runs out of clearance.

It’s probably a personal preference thing, but I found myself liking the way the diesel driveline handles itself off-road more so than the petrol model. Throttle control is easier and more relaxed, without ever needing to push above 2000rpm for the necessary go-forward. For rock crawling, it’s perfect.

The interior is a similar story to the petrol model. It’s a new design, but it’s 100 per cent Wrangler in terms of looks and heritage. The infotainment display is the newest 8.4-inch Uconnect system, with Android Auto, Apple CarPlay and native navigation. The operating system is fast and easy to use, and additional Off Road Pages give you some nice gauge readouts of coolant and oil pressures and temperatures.

There's decent space and comfort in the second row, along with stacks of power outlets: two USB, two USB-C and one 240V. There are also air vents and roof-mounted speakers that could potentially get in the way of taller folk.

Service costs for the diesel Wrangler Rubicon are $499 per visit, which are set at every 12 months or 20,000km. This is noticeably more expensive than the petrol Wrangler, which is listed at $299 every 12,000km or 12 months.

The Wrangler’s dismal one-star ANCAP rating does apply across the range, and is something that might turn buyers off the idea of Jeep’s off-road machine. Aside from crash safety, there is some decent active safety available: rear cross-traffic alert, blind-spot monitoring, forward-collision warning, autonomous emergency braking, adaptive cruise control and tyre pressure monitoring.

You never know, the Wrangler might have been able to double or triple its ANCAP rating if the tested vehicle had autonomous emergency braking fitted, but base models miss the tech, and ANCAP doesn't offer a split rating for the Wrangler like it does for some other models.

Jeep’s warranty offering covers you for five years or 100,000km, whichever comes first. That's good coverage for a half decade, but a few extra kilometres would be a nice addition. However, if you aren't going to do more than 20,000km per year, then it's a moot point.

Is the preference of diesel worth the extra five-large asking price Jeep wants for the 2.2-litre Wrangler Rubicon? Probably not. The petrol-powered model is every bit as capable off-road, and comes with a bit more refinement and straight-line urgency when needed. It will be a bit thirstier, though, especially around town.

Jeep lists 31.7 cubic feet (897 litres) of storage behind the rear seats of the Wrangler Unlimited, which is probably measured right up to the roofline. It's not a big storage space when compared to other 4X4 wagons, impeded by wheelarches, a big subwoofer and the internal rollcage.

There is a small section of folks that might like this diesel Wrangler, however, and might be keen to spend the extra dollars. Perhaps they’ve got their eyes on a map of Australia, and are keen to do some long-distance touring. For them, the better range and efficiency of the diesel will be enticing. You’ll have to concern yourself with the Selective Catalytic Reduction (SCR, AKA AdBlue) system, however, and pack light enough not to overburden the relatively meagre load space and payload (under 500kg).

However, you’ll have a touring 4x4 more capable than just about anything else on the market, which will give you confidence to tackle some seriously gnarly terrain anywhere in Australia. Although, I have to say, it’s a bit of a shame our Australian-specification Wrangler gets watered down with smaller tyres, smaller guards and a plastic front bumper compared to the tougher native North American versions.

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