Aussie engineering behind Toyota’s LC70

AUSTRALIA is one of Toyota’s strongest LandCruiser 70 Series markets, with one in five of all models produced sold here, which is why engineers spent 15 months testing and validating the durability and reliability of the new four-cylinder engine and automatic transmission combination Down Under.

Given its level of popularity, and the conditions LC70s are exposed to daily, it is perhaps no surprise that Toyota subjected its latest model to what it says was a gruelling local development program, ensuring the four-cylinder adaptation was an appropriate fit for the hard-working model.

According to Toyota, Australia has played a significant role in the development of its adapted four-cylinder powertrain, the HiLux-sourced engine and transmission undergoing a suite of changes to ensure its suitability in the demanding application, while simultaneously meeting Toyota’s strict durability requirements.

Part of the testing was replication of some extreme real-world use cases that LandCruiser customers in some of the most remote and harsh parts of Australia told the company their vehicles were required to perform in.

Local development of the new powertrain for the LandCruiser 70 Series began in 2017 when Japanese-based Toyota engineers flew to Australia to meet with the local engineering team and to witness first-hand how local customers use their LC70.

The crew travelled deep into the Australian outback, consulting farmers, remote area emergency services, park ranges, Aboriginal land councils, and forestry fire ranges who use the 70 Series in a range of applications – all of which involve heavy use in off- and no-road conditions.

Toyota Australia vehicle evaluation and regulations senior manager Ray Munday said the impact that the LandCruiser 70 Series has on remote communities was clear to see during the research trip.

He said feedback from customers highlighted a desire that the model retain its rigid front axle, 3500kg braked towing capacity, durability when traversing the toughest terrain, and continued compatibility with a wide range of accessories.

“This is a ‘contribution to community’ vehicle,” explained Mr Munday.

“It enables the livelihoods of a lot of people in Australia. When you meet these people and understand what this product does for people in the centre of Australia, it’s very hard to imagine from the comfort of cities like Sydney and Melbourne just how influential this vehicle is in enabling so many livelihoods.

“We spoke to a customer who would go out on feral animal control expeditions for a couple of weeks where they’d tow about 2000kg of aviation fuel.

“One (70 Series) was full of ammunition, one was full of camping gear, one was full of food and water, and they’d go out and camp for a few weeks in the middle of the outback about 700km from Alice Springs, driving across sand, riverbeds, doing this crazy work out in the middle of summer.

“To test the durability and capability of the new four-cylinder powertrain, we actually recreated that extreme scenario.”

That ‘extreme scenario’ was critical to ensuring the LC70 functioned to requirement when handed over to customers, and following the initial reconnaissance in 2017, four prototype vehicles equipped with the four-cylinder engine were freighted to Australia in 2019 as part of a real-world development and evaluation program for the assessment of long-term durability.

According to Mr Munday, engineers “torture tested” the 1GD-series engine and six-speed automatic transmission in a broad range of hardcore usage scenarios based on customer requirements, with heavy towing testing up hills, in low-range scenarios, sand climbs and mud and water crossings.

Rock climbing at maximum GVM and outback driving in dusty driving situations with multiple accessories fitted also formed part of the testing process.

“A lot of the planning was how we could make the vehicle most suitable for these types of customers,” he added.

In total, approximately 15 months of testing and validation was performed in Australia, helping engineers to understand the durability and reliability of the four-cylinder engine and automatic transmission.

In 2021 and 2022, further long-distance durability and reliability testing was conducted in harsh Australian conditions, with changes to the powertrain’s gearing, cooling and mounting systems developed using feedback from the first round of testing.

Modifications were made to the HiLux-sourced engine to “ensure its long-term durability and capability operating in often harsh conditions for extended periods”.

The most significant change has been to the oil pan which has been redesigned and is now made from pressed steel compared with the cast aluminium used in other models.

The shape and construction of the oil strainer and oil level sensor have also been updated to optimise performance, while the oil filter is oriented more horizontally to reduce potential damage in off-road environments.

To ensure optimal engine cooling under heavy-duty use such as towing and low-range off-roading, a larger-diameter cooling fan has been fitted. The new fan increases the load on the V-ribbed belt, so engineers have adopted an isolation crank pulley to help control speed fluctuations and improve durability.

Mr Munday said the gruelling testing regime showed the immense capability of the four-cylinder engine, aided by the performance of the automatic transmission which provided particular benefit in difficult driving scenarios.

“The GD with the auto is actually an amazingly capable product,” he said.

“With the automatic transmission – especially for towing or driving on sand – it makes the power a lot more accessible. It’s a much easier vehicle to drive.”

For the first time since the current-generation LandCruiser 70 Series was introduced in 2007, customers will be offered the choice of two powertrains with the introduction of the 1GD-FTV 2.8-litre turbo-diesel four-cylinder engine.

Offering increased torque (+70Nm) and with around 10 per cent reduced fuel consumption compared to the V8, the four-cylinder engine is mated exclusively to a six-speed automatic transmission.

Despite its smaller capacity and fewer cylinders compared with the V8, the 2.8-litre turbo-diesel offers strong outputs of 150kW at 3400rpm, with a considerable 500Nm available from 1600rpm through to 2800rpm.

Fuel consumption is rated at 9.6 litres per 100km based on Toyota Motor Corporation figures achieved on a similar test to the Australian ADR81/02 combined cycle test.

This engine is offered exclusively with a six-speed torque-converter automatic transmission, offering “simple and reliable operability in all conditions while being well suited for fleet applications where drivers may not be familiar or comfortable operating a manual transmission”, says Toyota Australia.

The AC60 transmission has also been tried and tested in other heavy-duty Toyota vehicles over a long period of time and has likewise been bolstered with enhancements to improve cooling performance.

The transmission oil capacity has been increased with the fitment of a deeper oil pan, allowing more stable distribution of oil pressure when driving on uneven slopes by optimising the oil strainer intake position and adding a transmission breather system oil catch tank.

Driving performance through bodies of water has been improved by adjusting the tip of the breather hose to 900mm above ground level, while a guard has been installed to protect the lower surface of the oil pan in harsh off-road conditions.

Along with the ease provided by two-pedal driving, the six-speed automatic transmission provides further benefit with a Power/Haul drive mode to optimise performance when towing or increased power is demanded.

A second gear start switch makes it easier to get out of sticky situations when off-roading, bypassing the first gear and starting in second, to provide powerful start-off acceleration in slippery or low traction conditions.

Manual gear shifting is also available via the shift lever.

Mr Munday said the addition of a sixth gear (with a gear ratio of 0.58) ensures “relaxed engine operation at freeway speeds”, helping to reduce engine noise and improve fuel consumption.

The 1GD engine will be offered alongside the beloved and long-standing 4.5-litre turbo-diesel V8 engine, that is paired with a five-speed manual transmission.

Maximum outputs remain the same with 151kW of power at 3400rpm and 430Nm of torque available over a wide rev band, from a low 1200rpm all the way through to 3200rpm.

Carryover combined cycle fuel consumption from previous ADR81/02 testing is 10.7 litres per 100km.

All LandCruiser 70 Series grades employ a part-time four-wheel drive system with a low-range transfer case, with GXL grades adding standard front and rear locking differentials.

Fuel tank capacity stands at a generous 130 litres across the range with the exception of the Troop Carrier, which expands to a formidable 180 litres split across two separate 90-litre tanks.

A highly rigid ladder-frame chassis supports rigid live-axle suspension with coil springs and an anti-roll bar at the front and semi-elliptic leaf springs at the rear, matched with hydraulic power steering.

Stopping power comes from four-piston fixed front calipers on 322mm x 32mm ventilated discs, with single-piston floating calipers at the rear mated to 312mm x 18mm ventilated discs.

As part of the 70 Series update in 2022, gross vehicle mass (GVM) was increased to 3510kg, allowing for increased payload.

Payloads range from 1060kg to 1380kg, depending on the grade and body-type allowing for generous load-hauling and the fitment of accessories without overstepping the maximum GVM.

All grades continue to offer a maximum braked towing capacity of 3500kg regardless of engine and transmission choice, with the automatic transmission designed to provide strong towing performance in tough conditions such as sand and off-road driving.

“Toyota has forged a deep connection with many of Australia’s rural and regional communities, a bond that continues to this day. Let me tell you, it is a bond that we never take for granted,” said Toyota Australia vice president of sales, marketing, and franchise operations Sean Hanley.

A Toyota mandated embargo means GoAuto cannot its report driving impressions of the vehicle until later in December. Visit GoAuto again soon for our drive impressions of the 2024 Toyota LandCruiser 70 Series.