What's a better piste-basher - Merc G63 or McLaren 720S?

The ultimate mountain car. Could it be the Mercedes-AMG G63? Or the McLaren 720S? Clearly some serious study was needed into this earth-shaking dilemma of our times.

No. Of course not. Look, here’s what happened. Rowan Horncastle, a man who, like me, gets a bit giddy around mountains, drove the Top Gear Garage Merc-AMG G63 out to Geneva for the motor show, with a plan to bolt a couple of days skiing on the back end. Then McLaren got in touch. Would we like to drive a 720S back to the UK from Switzerland for them? Via two days in the Alps, we asked. That’ll be fine, came the reply.

Words: Ollie Marriage // Photos: Rowan Horncastle

Now, contrary to expectations, opportunities like this don’t proliferate like flies on muck. But here we were, now with two of the wildest outliers of the automotive kingdom at our disposal. And less than an hour away were the snow-covered Alps. And they were parked in Palexpo’s underground car park, right underneath our sore feet as we hobbled from interview to interview.

Knowing a combined 1,287bhp lay beneath made it hard to concentrate on our jobs. Until we remembered that, technically, taking them into the mountains was also our job (we have good jobs). We left the show at lunchtime.

An hour later I was getting naked in a layby. Driving a McLaren while wearing a suit is fine, but not once you’re within the bounds of a ski resort. There you look a plonker. And are very cold. So I got colder, then warmer, and breezily informed Rowan that there was no need to employ the full carrying capacity of the G63, as I would now be carrying one pair of skis on the McLaren. This is because supercars aren’t cool, but supercars wearing skis are cool.

Rowan knows exactly where I’m coming from, as he was my partner the last time I came up with an excuse to go skiing, er, sorry, lost myself for a moment there: conducted a very valid, real world relevant practicality test of an exotic sports car.

Seasucker racks are very simple and very clever. They suction on to the roof and hold stuff: bikes, surfboards, fishing rods, roof racks. Traditionally fitting stuff to the outside of a supercar is something that car stylists and engineers have failed to factor into the design process. Top Gear is here to show them the error of their ways.

Mind you, the 720S is proving a tricky customer. The forward rack just fits across the glass panel, but as that narrows further back one side of the rear rack has to clamp itself to the curved flank. That it manages that speaks volumes for the Seasucker’s quality. I insert the skis and realise I can’t now open the upward opening doors. A mild inconvenience. Positional fiddling occurs and the skis are shunted over to one side.  

I climb in. We’re just outside the French resort of La Clusaz, home to one of my all-time favourite skiers, Candide Thovex. You’ll know him from the Audi ‘Ski The World’ quattro advert. If you haven’t seen it, look it up NOW. We might be getting some looks, but a McLaren wearing skis is less out of place than a bloke skiing the Great Wall of China. Anyway, I’ve bought Rowan this way so we can do some driving: from La Clusaz to Megeve via the Col Des Aravis. It’s not only a good road, but has the key benefit of almost always being open during winter.

Say what you will about tenuous feature ideas, but it’s an interesting comparison driving these two across here. Both are wearing winter tyres. Neither feels particularly happy about it. Having initially blown very hot about the G63, I’ve cooled my opinion since. 16mpg everywhere has that effect. More than that it’s a bit of a draining thing to tool around in. It’s massive, heavy, obnoxious and too fast for its own good. It’s not that big inside, the driving position isn’t relaxing enough. It’s amusing alright, but not very able. After a few days with it, I find I’ve had enough.

Mind you, a few minutes in the old one was more than enough, so it’s definitely progress. But it’s a clumsy great thing, one of those worryingly rapid devices that never knows when to quit and will merrily be able to drive back up from the bottom of whatever ravine it’s blindly hurled itself into. I’m leading in the McLaren, and I’m nervous. Those round headlights stare blankly back from behind, giving the Merc a gaunt malevolence. And then Rowan blips the throttle and I watch the G rock to one side.

The McLaren has troubles of its own. These are mainly caused by the tyres, the squidgy tread of which is flexing so much that the traction control is baffled. I can’t accelerate out of corners. At all. As soon as I touch the throttle coming out of corners the electronics decide there’s something fishy going on with the wheel movement, like it’s gone a bit spongy or something, and the power is cut. Only one thing for it: turn the electronics off.

Better, if additionally nerve-wracking. Now my second concern gets its moment in the spotlight: will the roofrack stay on? I’ve put the skis on with tips pointing up as Rowan says it looks better, but they’re catching more air that way up aren’t they? I’m not concerned about the 720S taking flight, but I am concerned about hearing a sucker pop loose and a split second after that watching a twisted scaffold of skis and rack plough through the G’s grille. Not that it would miss a beat. Probably just wear it as an ornament.

But I’m winning. Despite keeping exclusively to my side of the road, following every wiggle and straight-lining nothing, I’m still pulling a lead out. Remember the combine harvester in Cars? That’s what the G63 reminds me off. It thrashes along furiously in my wake, but just can’t keep up. I have had to use the McLaren’s engine. A bit. But on the whole I’ve been driving with my wrists. A McLaren on winter tyres is not a McLaren at its best. It’s a bit fuzzy, turn-in only occurring once the tread has got itself aligned, not when you ask the steering to do its stuff. But still, it’s zesty and eager and bright and airy and feelsome and really a rather lovely way of seeing the mountains.

Somewhere near Flumet I pull over and wait for the G63. Of course I hear it before I see it. I can pretty much smell it before that even. The poor brakes. Rowan is mildly hysterical. There’s laughter, but behind that, fear. All partially masked by relief. We swap cars, turn round and do it all again. The G is full of barrel-chested bravado, but while the engine is willing, the chassis is weak. It doesn’t like changing direction, downshifts are slow, the brakes have gone to mush, it heaves and lurches through direction changes. This is not the best terrain to show off the capabilities of our monster of the mountains.

Trouble is, as we prove a little later, neither is soft snow. The G is so heavy it refuses to scale a snowbank, instead dropping a wheel straight through. Of course it copes with snow and ice on road and in car park. But here’s the thing: so does the McLaren. Once you’ve engaged noselift and read War and Peace while waiting for it to rise, that is. It’s the car that feels the most special and peculiar out here, the one that people enjoy seeing the most, the one that gets catcalls from the chairlift above. The G63 – bet that belongs to the security detail, you can see people thinking.

I expect they carry on thinking it until we’re well out of sight. They wouldn’t carry on thinking it if they could see us loading up the McLaren’s front boot with cheap beer, cheese and baguettes outside a supermarket in St Gervais a bit later, ready for a spot of surprisingly affordable self-catering and beans on toast for dinner.