Mercedes-Benz GLS-Class vs Tesla Model X

What's the difference?

The GLS63 is an intimidating beast from afar, but it rewards its occupants in almost every way. Yep, there really isn’t a box it doesn’t tick without serious compromise, such is its breadth of capability.

If there was ever a Swiss Army Knife of cars, the GLS63 is definitely a contender for the title, one that makes it very hard to wipe the smile off your face. Just make sure you can fit it in your garage first…

After nearly 700km of testing with both cars, it’s fair to say that the Tesla is indeed a capable tow vehicle, provided you keep the distances relatively short and plan around charge station locations.

Overall average - Penrith to Bathurst to Penrith

Fuel and energy consumption will always depend on the driving conditions, which is why we chose different routes for each leg of our testing.

Averaged across the two legs, towing the caravan with the Model X used 101 per cent more energy than without, or halved its driving range, which sounds a bit scary.

The LandCruiser by comparison added 63 per cent on average, which is still a big difference, but matters less in the real world when its big fuel tanks would still give you about 760km of driving range, which can be refilled quickly at any diesel-stocked servo.

So you could do a weekend trip with the caravan from Penrith with one supercharge in Bathurst, but it would’ve been highly unlikely to manage the extra 55km if you were leaving from Sydney CBD.

The bottom line is that there’s plenty of things - like smaller camper trailers - lighter than our caravan that will help the Tesla to do the towing job better right now.

Compared to the ‘Cruiser, the Tesla is a lesson in the benefits of a lower centre of gravity and road-focused handling.

As always, bigger batteries and more recharge points will go a long way to rectifying the Tesla’s towing shortcomings, and I'm sure we'll get there eventually.

But no matter what, its acceleration performance under load is simply excellent.

Thanks to our friends at Avida for making this test possible with the use of the 17-foot Avida Wave Tourer Electric Pop-Top single-axle caravan. They can also be reached on 1300 428 432.

Frankly, the GLS63 has absolutely no right being as capable as it is. It’s a really big bus that’s legitimately convinced it’s a sports car half its size.

Being a GLS variant, the GLS63 has independent suspension consisting of four-link front and multi-link rear axles with air springs and adaptive dampers, but its party trick is the addition of active anti-roll bars.

In what feels like magic, the GLS63 is simply not intimidated by corners, despite having massive dimensions and a considerable 2555kg (kerb weight) to deal with.

The active anti-roll bars make the GLS63 so much easier to drive fast through the twisty stuff, almost eliminating body roll, taking one key variable out of the equation for the driver. Active engine mounts are also fitted, helping to settle things even further.

The electric power steering on hand is also good. It is speed-sensitive and has a variable ratio, which basically makes the set-up more direct when it needs to be. It’s typically light in hand, too, until one of the sportier drive modes is engaged and extra heft is added.

So, handling is scarcely believable, which means the ride must be compromised, right? Yes and no. With the adaptive dampers in their softest setting, the GLS63 is very compliant. In fact, we’d say it feels luxurious when compared to other high-performance SUVs.

That said, our test vehicle was fitted with the optional 23-inch alloy wheels ($3900), which look the part but expose sharp edges and other road imperfections, not to mention generate noise easily heard inside. Naturally, feedback is exacerbated in the sportier drive modes.

Anyway, there’s more performance, and the GLS63 has the rest in spades. Its engine is a powerhouse in every sense of the word. It’s so powerful, in fact, that it hilariously hunkers down off the line or when suddenly accelerating at low speed.

Thanks to the mild-hybrid system, wads of torque is available from the get-go, making for a highly responsive driving experience, even in those rare moments when the engine isn’t on song.

While not as characterful as some of the other members in the 63 series, the GLS63 still makes some thoroughly entertaining noises, with its sports exhaust system popping like mad while on the overrun.

All of this ability is very well and good, but you need to be able to pull up quickly, and the high-performance braking package (400mm front and 370mm rear discs with six-piston fixed callipers and single-pot floating stoppers respectively) mercifully does exactly that.

Energy consumption is just one element of a tow vehicle though, with stability, braking and acceleration performance being the most important details.

The big ‘Cruiser is always a safe bet for towing heavy loads, but it's fair to say its off-road ability, tall body and short wheelbase mean it could be better on the road, and the Tesla goes some way to proving that.

With all those batteries mounted nice and low, the Tesla is significantly more stable with 1.7 tonnes on the back than the LandCruiser, in all conditions. It’s also helped by that longer wheelbase.

The Tesla’s airbag suspension is another surprise advantage, and while it can be a bit choppy around town over minor bumps, bigger bumps on the highway are soaked up really nicely and it all settles quicker than with the LandCruiser - even with the caravan on the back.

Tesla is famous for instant acceleration at any speed, and this effect remains when towing. The LandCruiser’s twin-turbo V8 (with max torque available from 1600-2600rpm) has long been a benchmark for tow vehicles, but the Model X makes it feel sluggish by comparison.

You know how caravan vehicles are usually the slow ones up hills? This time, we were the ones doing the overtaking, even up the steep bends heading out of Lithgow. To overtake, it just takes the slightest flex of your right foot.

Clearly there’s a big caveat though when it comes to how much energy it’s consuming while you’re enjoying that performance, and it’s deceptive because it doesn’t make any more noise like a conventional engine when you’re pushing it. 

You’d also think the weight of the van would overcome the engine-braking effect of the regenerative brakes, but they are still very effective at conserving your brakes downhill and preventing the car from running away from you, and no doubt giving the batteries a bigger boost at the same time.

On that note, the LandCruiser’s cruise control also does a great job of witholding speed on downhill runs, proactively dropping gears to engine brake enough to keep the Avida Wave in check.