Lexus GX 550: Twin-Turbo V6 Replaces the Legendary V8

For over a decade, the Lexus GX has been an automotive anomaly. It was an old-school, body-on-frame SUV with a naturally aspirated V8 that refused to die. Now, the 2024 GX 550 has arrived to replace the GX 460. It brings a controversial new engine, a boxy design, and a dedicated off-road trim called the Overtrail. The big question remains: does the new technology compromise the legendary reliability that made the GX an icon?

The Engine Swap: Trading Displacement for Boost

The most significant change in the GX 550 is under the hood. The 4.6-liter V8, known for its bulletproof durability (and terrible fuel economy), is gone. In its place sits a 3.4-liter twin-turbo V6.

For purists, losing the V8 is painful. However, the numbers favor the new engine heavily. The old V8 produced 301 horsepower and 329 lb-ft of torque. The new twin-turbo V6 cranks out 349 horsepower and a massive 479 lb-ft of torque.

This torque increase transforms the driving experience. Where the old GX 460 had to downshift aggressively to climb hills or pass on the highway, the GX 550 surges forward with minimal effort. This engine is paired with a 10-speed Direct-Shift automatic transmission, replacing the ancient 6-speed. This combination allows for a towing capacity of up to 9,096 pounds on specific trims, a significant jump from the previous generation’s 6,500-pound limit.

The Overtrail Trim: Factory-Built for the Wilderness

Lexus saw what owners were doing to their older GXs—lifting them, adding chunky tires, and taking them overland. The new Overtrail and Overtrail+ trims are the factory’s response to this enthusiast culture. This is not just an appearance package; it involves serious mechanical upgrades.

The Overtrail trim includes:

33-inch Toyo Open Country A/T Tires: These are mounted on 18-inch wheels. Lexus wisely chose smaller wheels to allow for more tire sidewall, which is critical for airing down off-road.
Electronic Kinetic Dynamic Suspension System (E-KDSS): This is the magic behind the ride. It allows the stabilizer bars to lock for flat cornering on pavement and unlock independently off-road for massive wheel articulation.
Rear Locking Differential: An electronic locking rear diff is standard on Overtrail models. This ensures both rear wheels spin at the same speed to power through mud, sand, or snow.
Multi-Terrain Select (MTS): This software manages wheel spin across different surfaces like Dirt, Sand, Mud, and Deep Snow.

One specific trade-off to note: The Overtrail models come exclusively as two-row, five-seater vehicles. The third row is deleted to accommodate a flat load floor and potential camping gear.

Assessing Reliability: The Turbo Question

The snippet asks if the new engine lives up to the GX’s reliability fame. The previous 4.6L V8 was arguably one of the most reliable engines Toyota ever built. The new V35A-FTS twin-turbo V6 has a different track record.

This engine is shared with the Toyota Tundra and the Lexus LX 600. Early versions of this engine in the Tundra experienced wastegate issues and main bearing failures, leading to recalls. However, Lexus claims to have refined the manufacturing process significantly before launching the GX 550.

While a twin-turbo system is inherently more complex than a naturally aspirated V8 (more heat, more pressure, more moving parts), the bottom end of the engine is built to handle heavy loads. The GA-F platform, which the GX shares with the Land Cruiser and LX 600, uses high-strength steel and laser welding to maintain structural rigidity.

If you are buying for 300,000 miles of trouble-free driving, the V8 still holds the theoretical crown simply due to simplicity. But for the first 100,000 miles, the modern manufacturing tolerances of the GX 550 should provide a worry-free experience, provided owners adhere strictly to maintenance schedules. Turbos are less forgiving of late oil changes than naturally aspirated engines.

Interior and Tech: Modernizing the Cabin

The interior of the GX 550 balances luxury with utility. The dashboard is vertical and shallow, improving forward visibility—a crucial trait for off-roading.

The centerpiece is a 14-inch touchscreen interface. Thankfully, Lexus kept physical dials for the climate control and volume. You do not have to dig through menus just to turn up the A/C. The Overtrail trim features durable NuLuxe synthetic leather seats that are easier to clean than semi-aniline leather found in the Luxury trims.

Space is improved, particularly in the second row. However, in the seven-seat configurations (Premium and Luxury trims), the third row remains tight and is best reserved for children. Cargo space behind the third row is minimal, but with the seats folded flat, the volume is competitive for the class.

Pricing and Competition

The 2024 Lexus GX 550 has moved upmarket in price.

Premium: Starts around $64,250.
Overtrail: Starts around $69,250.
Luxury+: Can exceed $81,250.

At this price point, it competes directly with the Land Rover Defender 110. While the Defender offers a smoother unibody ride and arguably more brand cachet, the Lexus counters with superior resale value and lower expected cost of ownership. The new Toyota Land Cruiser is also a sibling competitor, but it comes only with a 4-cylinder hybrid powertrain. If you want the power of the V6, you must choose the Lexus.

Final Verdict

The GX 550 is a successful evolution. It trades a small amount of mechanical simplicity for a massive gain in performance, towing capability, and technology. The Overtrail trim proves that Lexus understands its customers, offering real off-road hardware straight from the showroom floor. While the long-term reliability of the turbo V6 cannot yet match the decades-long data of the old V8, the performance trade-off will be worth it for most drivers.

Frequently Asked Questions

Does the Lexus GX 550 require premium gas? Yes. To achieve the rated 349 horsepower and protect the turbochargers from knock, Lexus requires 91 octane (premium) fuel or higher.

Is the GX 550 hybrid? Currently, the GX 550 launches only with the twin-turbo V6. However, Lexus has confirmed a hybrid powertrain will be available in the future, likely pairing a battery system with the turbo engine.

Can the Overtrail trim fit in a standard garage? The GX 550 Overtrail is roughly 77.8 inches tall and 83.2 inches wide (with mirrors). It fits in most standard 7-foot garage doors, but if you have an older home with low clearance, you should measure first.

Does the rear window still pop open? Yes. Lexus kept the signature pop-out glass on the rear hatch. This allows you to grab gear or groceries without opening the entire heavy tailgate.