As we descend from the brow of the hill we are effectively in free fall. All the antilock braking, traction control and we'll-take-care-of-it-sir software in the world won't stop the Toyota from head-butting the earth's crust. Big time. And it does.

But it's hardly surprising. We are on a course designed to take the new Land Cruiser to the edge of its capabilities. It is Toyota's way of reminding us that the 51-year-old Land Cruiser legend has been built on its ability to keep going regardless.

Nearly 4m have been sold globally and it has been exported to 127 countries — including China, where it is called Shamowang, or King of the Desert. In Latin America the imaginative locals call it El Macho.

However, these are challenging times for old-school off-roaders. Relatively recent arrivals such as Mercedes's M-class and BMW's X5 might not be heroic in the mud but are vastly better to drive on tarmac. Lately Volkswagen has proved with the Touareg that you can combine sensational off-road ability with first-rate motorway manners. So 4x4 buyers have come to expect even the biggest off-roaders to drive more like saloon cars. To that end, the new Land Cruiser is laden with technology to give a range of suspension settings to suit your environment. At one extreme the comfort mode is meant to deliver a more absorbent ride over rough roads, at the other the sport setting firms everything up for twisty tarmac and tough cross-country conditions.

In comfort mode the suspension is good at soaking up big potholes and ruts. The ride over dips and crests remains bouncy and nervous, though, and the body tends to lurch slightly when you change direction quickly. Switching from maximum comfort to maximum sport did not produce a dramatic difference. I didn't expect it to turn into a Porsche, I just thought there'd be a more noticeable change. Sure, the body rolled a bit less in corners but the Land Cruiser is still a long way from delivering the best on-road experience for a 4x4.

Toyota has succeeded, however, in making the Land Cruiser much more refined. At 80mph wind, road and mechanical noise are remarkably low for such a big machine. The performance from the 161bhp turbodiesel is also up to the task — 0 to 62mph in 12.7sec, 106mph top speed — and all that low-rev poke delivers a relaxed drive. A 245bhp V6 will follow soon after the main launch in January but Toyota expects 98% of buyers to opt for the diesel.

The entry-level Land Cruiser will cost £23,995, and along with a cavernous interior you'll get air-conditioning and a CD player as standard. The £36,795 range-topper brings a mind-boggling specification that includes satellite navigation, air suspension and every electrical function known to man.

At that price, though, its more dynamic rivals from Mercedes, BMW and Volkswagen are all in the frame. But like the nearly beaten hero who has one round of ammo left the Land Cruiser shoots back. It remains unbelievably good at the rough stuff and is loaded with technology to help it descend hills without sliding out of control and to power up them even if only one wheel can find purchase.
Construction is still the old body-on-frame approach that Toyota says is better at taking maximum off-road punishment than the now more common all-in-one monocoque.

Gravity still poses a problem, though. After dozens of runs our long muddy hill has become less of an incline, more of a vertical drop. Gentle descent turns into hurtle and the big Toyota smacks the foot of the slope hard — only to bounce off and keep going. Because that's what Land Cruisers do.

Vital statistics

Model Toyota Land Cruiser
Engine Four cylinder, turbodiesel
Power 161bhp @3400rpm
Torque 253 lb ft @ 1600rpm
Transmission Five-speed manual
Suspension (front) double wishbones, coil springs, (rear) four link live axle, coil springs
Tyres 225/70 R17
Fuel 29.7mpg (combined)
CO2 253 g/km
Acceleration 0-62mph: 12.7sec
Top speed 106mph
Price £23,995
Verdict Struggling to keep up in terms of road dynamics, but still one of the best in the world when it comes to off road ability