Jeep Wrangler VS BMW Z4

The two-door Rubicon is rather ordinary to drive on sealed surfaces, but it isn’t anywhere near as diabolical as some people would have you believe.

This is a purpose-built off-roader with a wide wheel track and low centre of gravity, so it feels solid on bitumen and dirt in equal measure.

However, you do have to drive it with full focus and give yourself time to get used to some if its more quirky aspects if you aren’t already familiar with them. There is plenty of play in the steering, lots of on-road floatiness and body roll, and this Rubicon – tipping the scales at 1977kg tare weight (listed) and measuring 4334mm long (with a 2459mm wheelbase), 1894mm wide and 1879mm high – can be an unpredictable unit.

You need to micro-manage this shorty 4WD at all times. It’s like driving a go-kart, but more fun and – bonus – it’s street legal.

If you’re steering it, this short-wheelbase Rubicon demands your constant attention – but that’s a fun characteristic I appreciate and that it shares with only a few other vehicles such as the Suzuki Jimny and Toyota LandCruiser 70 Series.

However, as fun as it is, this kind of fully engaged driving experience – requiring laser-focus concentration to keep a vehicle on target – asks a lot of the driver and does become tiring (nay, exhausting) after long stints on the road or off of it.

Beyond that though, this Rubicon, with a track-tight turning circle of 10m, is a nicely manoeuvrable vehicle around town (for swift turnarounds and easy parking) in the suburbs and even along overgrown bush tracks – but more about that soon.

Wrangler fans who have bemoaned the loss of the Pentastar V6 needn’t have worried. The new four-cylinder engine delivers a gutsy punch of acceleration when needed and is nicely matched to the eight-speed auto. It’s also smoother, more refined and less noisy than before.

The solid-axle Rubicon has a suspension set-up – including coil springs at every corner – that soaks up most bumps in the road, and that makes for impressive levels of driver and passenger comfort.

This little purpose-built rock-crawler is solidly built and it can get noisy when you’re inside of it as it rumbles along a road or track – no surprise because it does have a boxy body, big wing mirrors and chunky mud-terrain tyres. Part of the experience, part of the fun, I reckon.

So, how does it go off-road? Bloody well, as usual.

The Rubicon is a genuine 4WD with a dual-range transfer case, a ladder chassis, solid axles, well-established 4WD heritage and its boosted by driver-assist tech. It’s immediately more at home taking on low-speed 4WDing than it is negotiating suburban traffic, shopping centre car parks or city streets.

I’ve driven Rubicons in pretty much every kind of challenging off-road situation – sand, steep rain-slick rocky hills, deep mud holes, swollen water crossings – and they’ve never disappointed. 

These Jeeps are some of the few modern-day 4WDs engineered with an off-road focus that offers few concessions to anything other than dirt-track fun – the only vehicles in the same realm are the aforementioned Jimny, 70 Series, and even the likes of the Ford Ranger Raptor and Ineos Grenadier.

Steering in the chopped Rubicon retains a nice weight and feel to it during 4WDing, staying precise as needed, offering the driver a great sense of sustained control through even severe terrain.

Its planted stance gives the Rubicon a distinct composure and its suspension – with a coil spring at each corner – helped it to take the sting out of every dirt-road corrugation on the way to my unofficial 4WD testing and proving ground.

As mentioned earlier, anyone worried about the V6 being dropped should calm down. The new engine is a lively and punchy unit – even livelier than the V6 – and offers up ample smoothly-delivered torque across a wide spread of revs, ideal for high- and low-range 4WDing.

When you switch to 4L and drop the revs, it’s easy to squeeze the most out of this new engine. Considered driving is necessary as is slow and steady throttle, but that's easily achieved in this Rubicon and it was never overworked even when the terrain became very challenging.

This Jeep has a well-calibrated off-road traction control system but if you need even more terrain-grabbing magic, it has front and rear diff locks, and a front sway-bar disconnect system, which helps to unlock even more articulation, and let those tyres stretch to the ground for all-important traction.

The Rubicon also has Selec-Speed Control (an adjustable low-speed cruise control for 4WDing that can be set between 1.0-8.0km/h), and Off-Road+, which adjusts throttle and traction control, among other systems, to best suit the terrain.

What’s also handy about the Rubicon is that, via the off-road pages on the multimedia screen, you can monitor your 4x4 system, as well as vehicle steering angle, pitch and roll, and the status of the diff locks and the swaybar disconnect system.

The two-door Rubicon has a listed 257mm of ground clearance and 760mm wading depth. While I didn’t experience any water crossings that deep this time, I did do plenty of driving on coastal sand, just inland from a beach, and there were deep rutted sections, so I saw clear evidence of its running clearance.

When it comes to approach, departure and ramp-over angles, the higher the number the better and the short-wheelbase Rubicon checks out with listed measurements of 44, 37, 27.8 degrees respectively, and this small 4WD climbs up and over even steep rocky hills with sharp crests, without ever being in danger of scraping the earth with its front, under-carriage or its back end. 

The Rubicon rides on BFGoodrich Mud-Terrain KM2 (255/75R17) tyres – real muddies – and those are strapped to 17-inch alloys. These are good tyres and the 17-inch set-up is good for off-roading.

The shorty Rubicon is not a big vehicle and so its Gross Vehicle Mass (GVM, 2404kg) and Gross Combined Mass (GCM, 3751kg) are not massive figures.

It’s not renowned as a towing platform of note but it pays to know that its tongue download is 150kg, towing capacity is 750kg (unbraked) and 1497kg (braked).

A car that looks this good better live up to the promise behind the wheel, right?

For the most part, the 30i does, but it’s a victim of its own performance credentials and luxuriousness.

See, a drop-top should be fun-packed, you should feel close to the road, connected. Sadly, a combination Z4’s excellent suspension and not-so-excellent SUV-like interior separates you too much from the surface below.

An advantage, of course, is the refinement on offer. The Z4 is easily one of the quietest, most refined convertibles I’ve ever driven, but it’s a little too insulated.

I can’t help but feel like it’s all business and no pleasure. It feels a little more like I should be cruising to work on the autobahn and a little less like I should be flinging it around corners on a tight B-road.

It feels almost wrong to drive it in a T-shirt. It’s serious and doesn’t want you to mess around, it wants you to wear a suit and tie.

This grand-tourer style feel is one that will keep a lot of buyers in the premium space happy, but I’m of the opinion that BMW will have that segment well and truly covered by the new 8 Series. If the budget allows.

Regardless, the 30i’s four-cyl engine feels like any six-cylinder would have a few years ago. It’s got a surge to it in the straights that’s quite satisfying, and it responds via the exhaust with an angry tone that makes it feel a little more alive, especially with the roof down.

This feeling was all helped along by our car’s M active differential which simply won’t let the fat tyres at the rear slide unless you’ve got high-speeds and loads of tarmac to play with – for better or worse.

The Z4 also has ‘variable sport steering’ which reacts to the car’s speed and position of the wheels to adjust the input ratio. It’s good when you’re at speed, but the weight and response of the steering can make the Z4 feel bigger than it actually is at lower speeds. 

The suspension is firm, and can be a little bouncy over rough surfaces, but seems well suited to the Z4’s chassis.

Other than those notable characteristics you’ll find that the Z4 is wonderfully tuned in terms of its inputs, everything is slick and smooth, suited perfectly for long meandering drives.