Is Toyota V35A-FTS Engine Reliable? Well..It's Not That Simple

Summary

The video explores the Lexus GX550's new V35A FTS engine, which boasts a smaller 3.4 L twin-turbo V6 yet delivers impressive torque and power, comparable to larger engines. The chief engineer explains the '550' designation and discusses the engine's high-speed combustion technology, aimed at achieving both high thermal efficiency and reliability. Despite these advancements, concerns arise over potential main bearing failures, as highlighted by a Lexus technician's experiences. Overall, the video delves into the complexities of modern engine design, balancing performance and durability in the evolving automotive landscape.

Takeaways

• 😀 The Lexus GX naming convention reflects engine displacement, with the new GX550 featuring a smaller 3.4L engine yet producing power comparable to a 5.5L engine.
• 🚗 The new V35A FTS engine provides 479 lb-ft of torque, which is a 46% increase over the previous V8 engine, showcasing impressive performance from a smaller engine.
• 🔧 The V35A FTS engine was first introduced in the 2018 Lexus LS and is now found in various models like the Land Cruiser and Tundra.
• 📊 Smaller turbochargers are used in the GX550 compared to other models, allowing for better low-end torque and drivability, essential for off-roading.
• 🔍 The bore and stroke configuration of the new engine is under-square, which is typically associated with better low-end torque.
• ⚙️ The chief engineer emphasized that bore and stroke are only one part of many factors that contribute to the engine's performance.
• 🔋 Toyota aims to maintain reliability despite higher power output by increasing combustion efficiency, leading to less wear and tear.
• 📄 A scientific study revealed that Toyota's high-speed combustion technology allows for high thermal efficiency and specific power, overcoming typical trade-offs.
• 🛠️ There have been reports of main bearing issues with the V35A engine, raising concerns about durability despite technological advancements.
• 🤔 While Toyota has made improvements to the bearing materials, anecdotal evidence suggests ongoing issues with main bearing failures in specific engine models.

Q & A

Why is the new Lexus GX550 named '550' despite having a 3.4L engine?

The '550' designation indicates that the engine outputs power and torque comparable to a traditional 5.5L V8 engine, even though it has a smaller displacement.

What significant improvement does the new twin-turbo V6 engine offer compared to the old V8 engine?

The new engine produces 479 pound-feet of torque, a 46% increase over the V8 in the GX460, and this torque is achieved at lower RPMs, providing better drivability for off-roading.

How does the bore and stroke of the new engine differ from the old V8?

The old V8 engine had a large bore and short stroke (over square), while the new V6 engine has a smaller bore and a longer stroke (under square), which is generally associated with better low-end torque.

What is meant by 'high-speed combustion' in the context of the new engine?

High-speed combustion refers to an improved combustion efficiency that allows the engine to produce more power with less fuel, reducing stress and wear on the engine components.

What are the concerns regarding the reliability of the new engine compared to older Toyota engines?

The new engine's higher output from a smaller displacement raises concerns about increased wear and tear, but the chief engineer assures that they maintain the same standards of durability as previous models.

What has been reported regarding main bearing issues in the new engine?

Technicians have reported main bearing issues in the LX600, which uses the same V35A engine. These problems have occurred even in vehicles with low mileage, suggesting a potential design or manufacturing concern.

How did Toyota address the main bearing design in the new V6 engine?

The new V6 engine uses metal overlays for the bearings instead of resin liners, and the main bearing caps have been redesigned for increased rigidity to better support the engine's higher loads.

What is the relationship between engine displacement and thermal efficiency?

Typically, as engine displacement decreases, achieving higher specific power can lead to reduced thermal efficiency, resulting in more wear and tear. However, Toyota's new engine aims to balance both by using high-speed combustion technology.

What did the chief engineer say about the concerns of overstressing the smaller engine?

The chief engineer explained that despite the smaller engine working harder, it achieves higher combustion efficiency, which allows it to create more power with less stress compared to traditional engines.

What steps can car enthusiasts take to better understand the new engine technology?

Enthusiasts are encouraged to educate themselves by reading scientific papers and technical documents that provide in-depth explanations of the engine's design and performance characteristics.