2024 Lexus GX Ready for Off-Road Adventure with New Platform, E-KDSS

Engineers designing the 2024 Lexus GS, shown here in Overtrail trim, wanted to leave no doubt as to its overlanding bonafides.

Once Toyota finally updated the Tundra to its third generation in 2022 after 15 years on the last-generation platform, the next model that would logically contend for an overhaul was the Lexus GX. Last given a generational overhaul in 2009, the new GX has been a long time coming. Chief engineer Koji Tsukasaki said the updates are more than just overdue, they’re for overlanding.

“We were going to build a Lexus that had never existed before, a true authentic offroader that would be held as the reference point for everything moving forward, and we boldly changed the positioning of the vehicle when starting development,” Tsukasaki told SAE Media, as translated by an interpreter provided by Lexus.

The 2024 Lexus GX offers 24 inches (621 mm) of articulation thanks to its electronic Kinetic Dynamic Suspension System (E-KDSS).

The chunky new GX doesn’t hide its new identity. Thick lines keep the boxy shape from being just another Land Rover, even if that’s the obvious territory the designers were playing in. The signature Lexus grille is still huge, but the bottom of it has been moved up the fascia, and a protective element was added to the lower half to prevent damage from road debris. The lower section is even removable on the GX’s off-road-focused Overtrail trims. In short, the GX’s new look implies better off-road performance, but to clinch the deal, the engineers needed to do more than improve the exterior.

As part of the repositioning, Tsukasaki said, Lexus developed a three-prong strategy for its large SUVs. The new GX 550 became the “true offroader,” while the LX became the flag-ship model and the TX the best option for three-row SUV buyers. To make the GX perform better off-road, Lexus decided to base it on the new TGNA-F platform. While the older Toyota Tacoma and FJ Cruiser use the F2 variant, the GX, the LX and the new Toyota Tundra and Land Cruiser use the F1, which has a higher off-road performance capability than the F2.

“We determined at early stages that we were going to switch from the F2 platform to the F1 platform, the ones shared by the Landcruiser and LX because we wanted to create the true offroader package of the vehicle,” Tsukasaki said.

Fuel efficiency across all trim levels of the new GX is 17 mpg combined. There will only be one engine option available in the 2024 GX: Toyota’s reliable 3.4-liter V6 that produces up to 349 hp and 479 lb-ft (649 Nm). Depending on the configuration, the 2024 GX can tow up to 9,096 lbs (4,126 kg) in the Overtrail trim. The new GX can go from 0-60 mph (97 kph) in 6.5 seconds.

Off-roading with E-KDSS

Lexus’ off-roading history goes back at least to the LX 450 in the mid-1990s. The first GX, the GX 470, debuted in 2002, and the new Kinetic Dynamic Suspension System (KDSS) became available for the GX in 2003. KDSS improved stability by electronically controlling the sway resistance of the front and rear suspension anti-roll bars. Two decades later, Tsukasaki and his team improved the off-road capabilities of the new GX by introducing a new available feature: Electronic KDSS (E-KDSS).

The original KDSS decoupled the swaybar stabilizers using a hydraulic system, while E-KDSS uses electronic control. The engineering team knew decoupling the stabilizers was the best way to get extra articulation because it offered a way around the physical limits of continuously connected stabilizers.

“Creating an electronic system allowed us to solve one of the demerits of a hydraulic system, which was that the front and the rear systems were linked,” Tsukasaki said. “Now we’re able to independently control the front and the rear separately, so that’s how the electric system brings in a better advantage.”

The E-KDSS offers 24 in (621 mm) of articulation on the new GX, an improvement over the 22-in (559 mm) articulation in the new GX versions with standard KDSS and 21-in (535 mm) articulation in previous GX models with KDSS.

Electronic control was also a lower-cost solution and allows the GX to control the coupling and decoupling at more precise rates for better ride quality, he said. When on paved roads, the GX monitors steering angle, vehicle speed and lateral Gs to decide when to engage and disengage. The E-KDSS stabilizer is also thicker than it would be if it weren’t always being disconnected, which further minimizes body roll and increases body structural rigidity.

Turning the 2024 Lexus GX away from the ease of paved roads proves Tsukasaki and his team have improved the SUV’s off-roading chops to tackle modest trails and hills. Whether on the trail or a freshly paved suburban cul-de-sac, the new GX delivers a quiet, comfortable ride, especially given the body-on-frame structure at work.

There’s plenty here to help beginning off-road drivers, too. The Multi-Terrain Monitor uses visual feeds from the front, side and rear cameras to show what’s under the massive front end on the dashboard’s 14-inch display. An electronically controlled locking rear differential works with Downhill Assist Control (DAC) to keep the GX from accelerating out of control when on an incline. DAC can even be used in reverse gear if you’re attempting a trail that turns out to be too much.

Tires, too, with Toyo

Lexus is offering new 33-inch (838 mm) specially designed tires for the new GX. These all-terrain tires come standard on the Overtail and Overtrail+ trims and give the SUV 8.9 inches (226 mm) of ground clearance. The standard GX without the special tires rides a little lower, with 8.66 inches (220 mm) of clearance.

Toyota and Toyo Tire began working on these tires three years ago, Tsukasaki said, and engineers were focused on three main factors: reducing road noise, cooling performance, and aerodynamics. The tires’ side tread pattern was crucial in improving aerodynamics.

In addition to the GX, Toyota will use these new tires, or something very similar, in the new Land Cruiser, including the next 4Runner.

Toyota will start building the new GX at its Tahara plant in Japan in February 2024 and said it expects to sell more than 33,500 units in calendar year 2024. Whatever the sales numbers, Tsukasaki already sees success when he looks at the SUV. Despite the many challenges this team faced during the development process, they managed to reposition the GX how they wanted.

“When I look at the different parts of the vehicle, the faces of the engineers that worked on it pop up into my head,” he said.



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This article first appeared in the March, 2024 issue of Automotive Engineering Magazine (Vol. 11 No. 2).

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