The new Lexus LX450d could be the most powerful off-roader of 2018

It's been a long time coming, but Lexus finally has a diesel engine in its lineup.

Until now, the Japanese luxury brand has focused its fuel-saving efforts on hybrid systems that team a petrol engine with an electric motor.

But for the LX large off-roader there was no such solution, prompting Lexus to head down the diesel route for the first time.

Humble genes

Since arriving here 20 years ago the Lexus LX has been powered exclusively by a V8 petrol engine.

But the new LX450d has switched things up to include a 4.5-litre twin-turbo V8 diesel.

It's exactly the same engine also used in the Toyota LandCruiser and comes mated to a six-speed automatic transmission.

Performance per litre

The big V8 diesel is smooth and refined, making for easy highway cruising and punchy acceleration.

And, as expected, the diesel is far more frugal than the petrol engine, consuming around one-third less fuel according to the official fuel figures.

In a car this big that's important, and while you'll struggle to achieve the claimed 9.5 litres per 100km fuel use, the low-double-digit real world consumption is significantly more economical than any Lexus LX before it.


Down on the Range

That diesel engine also makes the Lexus LX a more serious rival to the mighty Range Rover, the car that started the whole luxury off-roader trend almost half a century ago.

While the Range Rover has come under fire from brands keen to tackle its luxury mantle – models from Bentley, Porsche and Lamborghini spring to mind - no brand has yet rivalled it for off-road ability until the LX.

Underneath, the LX shares its genes with the Toyota LandCruiser, arguably the most highly regarded car in the Aussie bush and outback.

As well as the engine, the basic body and architecture is shared with the humble Toyota, something that brings serious pedigree.

Rough and ready

Riding on adjustable height hydraulic suspension – something that differentiates it from the Toyota it's based on – allows its body to be raised by about 55mm, giving it excellent clearance over obstacles.

Combined with a low-range four-wheel drive system with the ability to lock the rear differential and utilise a tailored traction control system means you can cover rough terrain surprisingly easily.

It's a superbly capable machine for those prepared to venture off-road.

Keeping quiet

The active suspension does a terrific job of containing the high-riding cabin, automatically lowering about 20mm at higher speeds, in turn lowering the centre of gravity.

Like so many top-shelf off-roaders, it rides on sizeable wheels and tyres, in this case measuring 20 inches in diameter.

The relatively low profile tyres improve cornering precision and grip, but they are typically more easily punctured.

That said, we tried them on thousands of kilometres of often unforgiving roads and didn't get a puncture.

Numbers game

At $134,500 the Lexus LX450d is almost $10k cheaper than the LX570 that's still on sale.

On paper, then, it seems an obvious choice, given the fuel-saving benefits of the diesel engine.

But the diesel misses out on some of the luxury gear of the petrol V8 – and it's all because the diesel engine is heavy.

Things deleted include rear entertainment screens, heated/ventilated seats, heated steering wheel, the fancy 19-speaker Mark Levinson sound system (it makes do with an unbranded nine-speaker system) and a sunroof.

Room to move

The third row of seats has also been left out, making the LX450d strictly a five-seater (the LX570 has eight seats).

That's no bad thing: the Range Rover that is its prime rival seats only five people, too (the smaller Range Rover Sport can be configured as a seven-seater).

And without the seats taking up space in the load area, the LX450d has an enormous luggage area capable of swallowing plenty of holiday and travel gear.

Fuel for thought

The LX450d also misses out on the dual fuel tanks fitted to LandCruiser, something that reduces how far you can travel between refills; instead of a 138-litre tank, you get a 93-litre tank.

That's not a big issue if you're not planning to tow (it can lug up to 3.5 tonnes) or head into very remote areas.

But it means you'll be heading to the servo more often than a LandCruiser owner.

Daring stuff

Of course, one of the big issues with off-roaders as sumptuous as the LX is whether people will actually use them off-road.

There's a lot of leather and woodgrain to get dusty, something out of step with the gleaming paintwork in the brochure.

Being based on a LandCruiser means it will be taken seriously – plus, there's support if you need it.

While Lexus doesn't have an expansive dealer network, parent company Toyota does – and many of the parts you might need will be available at a Toyota dealership.