Yukihiko Yaguchi spent an unprecedented 40 years as an engineer for Toyota, ultimately rising to the head of Lexus’s high-performance F division, going toe-to-toe with the likes of BMW M and Mercedes AMG. In a rare interview, Michael Greenfield-Raban finds out how - despite retirement - Yaguchi-San hasn’t taken his foot off the throttle…
It has been a great honour to have the opportunity to interview Yukihiko Yaguchi, the brilliant mind behind the Lexus “F” brand. Yaguchi-san’s contributions to the world of motoring range from the development of the iconic Lexus LS400 and the A80 Toyota Supra to the creation of the first Japanese performance brand that rivalled the likes of the established BMW M, AMG, and Audi Sport. The “F” brand has created cars that have not only focused on outright performance but also on the raw thrill and enjoyment of driving a naturally aspirated V8 sports car, something that the Germans have since left behind. This adoption of “Kansei” engineering is seen in the modern-day RC-F as it still applies the use of a naturally aspirated engine eight years after the final V8 E92 M3 rolled off the production line in Regensburg.
Yaguchi-san retired from the Toyota Motor Corporation in 2020, but his legacy is still very much ingrained in the DNA of the current Lexus performance-orientated lineup as well as with Toyota and Lexus enthusiasts. Yaguchi-san was so respected by his board members at Toyota, he was bestowed with the honorary title of Emeritus Chief Engineer. Currently, he works as an Advisor for BBS Japan, and also runs the Office F. Regulus consulting business and blog that specialises in “product planning, product promotion methods, technical advice, support for motorsports and events, etc.” Interestingly, the name of Office F. Regulus is derived from the astrological “heart” or brightest star in the Alpha Leo constellation.
Presently, a normal day for Mr. Yaguchi begins at 8 A.M., when he heads to the gym. After an hour of stretching and cardio, he showers and proceeds to his desk. Since Mr. Yaguchi does not need to rush to morning meetings, he can casually go through his emails and check the news.
However, the schedule differs when Mr. Yaguchi has business appointments. For example, in his role as Advisor for BBS Japan, Mr. Yaguchi is deeply involved in a variety of areas as product planning, technical advice, creating methods of product promotion as well as providing support for motorsports and events. In addition, Yaguchi-san provides business consultation for clients of Office F. Regulus. Then there is his work as a lecturer, which includes a part-time role at the Toyota Tokyo Automobile College and speaking arrangements at various events and organisations. Some examples of Mr. Yaguchi’s prior speeches include a lecture on the central theme of the development of the Lexus F models which is enjoyment derived from cars and also a speech on the new era of branding and how brands are no longer exclusive to corporations.
During a career at Toyota that lasted over forty years, Yaguchi-san has been involved in some of the most significant projects in the company’s history. Mr. Yaguchi’s work has encompassed the first four generations of the Toyota Supra, including the final specification of the A80 and its Japanese market Yamaha REAS suspension system. One of Yaguchi- san’s cherished experiences has been his work as Development Leader of the Lexus LS400, particularly with regards to NVH.
Not only did Yaguchi-san lead the development of Lexus’ first offering, but also organised Lexus’ Planning Department and the marque’s brand strategy. In addition, Yaguchi-san’s portfolio includes production planning and performance development audits for iconic Toyota models as the Chaser and Century. Later on, Yaguchi-san had the opportunity to create a sub-division of Lexus tasked with developing performance Lexus models with an emphasis on the thrill of driving, this was the F brand. During his tenure as leader of the “F” sub-division, Yaguchi-san was the Chief Engineer for the V8-powered IS-F saloon, RC-F coupe, and elegantly understated GS-F.
While he is not currently involved in any car development projects, Mr. Yaguchi still enjoys his Porsche 718 Cayman by driving to holiday and business destinations. He is also very much involved in the enthusiast car world and takes pleasure in attending local car events and speaking with fellow enthusiasts. Yaguchi-san is also happy to work on his cars, “In the past, I used to do various maintenance and tuning up by myself, but now I don’t have a maintenance space, so I only do light work like changing to winter tires.” However, Yaguchi-san is not only a car person, he also loves to ride motorbikes, but respects the wishes of his family and abstains. Mr. Yaguchi has an appreciation for art and architecture, which may have had an indirect influence on his work.
Yaguchi-san enjoys quiet evenings with his family, indulging in film and books and appreciating an occasional drink. As we find ourselves at a critical juncture in automotive history, Yaguchi-san was very kind to share his perspective on the past and future of the performance car.
MGR: Stringent vehicle emissions standards have been forcing manufacturers to stop selling performance cars with large displacement engines and instead develop electric vehicles. Where do you believe the future for car enthusiasm and the performance car lies?
YY: In order for people to enjoy cars with peace of mind, we cannot turn away from environmental measures. I think that even if the power unit of a fun car or a high-performance car changes, the three elements that people enjoy will not change. It is the response to human operation, sensual sound, and pleasant power characteristics, which are also the three elements of fun of the F model. Development should be done in line with this. However, I feel that the current BEV is still under development to establish a BEV that is fully compatible with these three elements. I look forward to it in the future.
MGR: What are the 3 road cars that you wish to drive, but have not had the opportunity to do so?
YY: There are several road cars that I wanted to drive, but I'll list three. Ferrari Dino GT4, Aston Martin DB5, and Fiat Abarth 131 Rally.
MGR: “Restomodding” has become a common practice in the past decade. If you were to “restomod” a Toyota Supra (A80), what improvements or adjustments would you make, if any?
YY: I was involved in the development of the final specification for the Supra 80. It is the development of Yamaha REAS suspension that was only for Japan. If you want to restore the Supra 80, I would like to use it for a homologation model for Group A like the one in the Supra 70. Aerodynamics, cooling improvement exterior, engine fine tuning and weight reduction.
MGR: Many car or racing engineers focus on one aspect of a car throughout their careers. For example, Colin Chapman had the famous motto “Simplify, then add lightness”, and Enzo Ferrari also said that “I don’t sell cars. I sell engines. The cars I throw in for free since something has to hold the engines in.” Is there an aspect of car engineering that you have focused on throughout your career?
YY: Automotive engineering today has almost the same idea all over the world. What I'm paying attention to is that the car is a machine, but it's a human being who drives it. That means driving and having fun. We have emphasised the correctness of Kansei engineering, that is, the enjoyment, rather than the correctness of automobile engineering.
MGR: Of all the automotive projects that you have been involved in throughout your career, which are you most proud of?
YY: There are two epoch-making vehicle developments in my career. One is the development of the first LEXUS LS400 (released in 1989), which was able to establish the base technology and my work style as an engineer. The other is the LEXUS IS F (released in 2007), my first car as a chief engineer.
MGR: While the Lexus RC-F has been greatly praised for its wonderful naturally aspirated V8, especially since many of the RC-F’s rivals now use turbocharged engines that lack soul and sound qualities. The RC-F has been equally criticised for having a higher kerb weight than many of its rivals. For example, the BMW M4 has a 228 kilogram weight advantage over the RC-F. How do you view the compromise of the added weight of the RC-F?
YY: The LEXUS F model has a LEXUS base model. Naturally, the base model is prioritised in vehicle development. It must comply with safety and durability as a LEXUS, which is stricter than the world standard. When developing F, I thought of two answers. I have developed the basic F model so that anyone from public roads to tracks can enjoy it seamlessly. Subsequently, we developed the lightweight version as a track version. The IS F CCS-R (Circuit Club Sports Racer) is more than 300kg lighter than the base car, with body reinforcements, roll bars, cooling system enhancements and aerodynamic improvements. Similarly, with RC F we also developed the GT Concept. Unfortunately, the official sale did not come true. However, we jointly participated in the Nürburgring endurance championship with the IS F CCS-R with the German team and won the class championship for the third consecutive year.
MGR: Are there any ideas or features that you would like to have implemented in the Lexus “F” cars but could not due to regulations, developmental budgets, or other practical concerns?
YY: There are many things I wanted to achieve with the LEXUS F model. Among them, the following could not be implemented. First of all, the release of a lightweight model. Also, a Convertible F model, and a new power unit including transaxle transmission, etc.
By now, hopefully, you have read our interview with Yukihiko Yaguchi. What stood out to me from the interview was Yaguchi-san’s priority on developing cars that focus on driver enjoyment, rather than outright pace and competence. Consequently, all Lexus F cars since the original IS-F have been powered by the naturally aspirated Yamaha-built 2UR-GSE 5 litre V8 for its aural quality, linear torque curve, and smooth power delivery in comparison to other sports and super saloons with turbocharged motors. The world of the performance car has changed immensely over the past decade or so, and as evident from EVO magazine’s recent feature on some of the last V8 rear wheel drive coupes, the current RC-F is unfortunately one of the last of a breed of naturally aspirated, pure combustion driver’s focused sports coupes. The RC-F’s engine however, does not represent a relic from ancient history, but rather a quite potent 472 horsepower V8 that features lightweight forged and titanium internals, direct and port fuel injection, and a robust oiling system with a scavenge pump allowing for high-speed cornering with sustained g-forces, giving bulletproof reliability.
The Lexus F brand was born out of Yaguchi-san’s desire to create a Lexus driver’s car that could be enjoyed by both driving mortals and driving gods. This principle, along with a focus on engine emotion and the impeccably high Lexus quality, reliability and safety standards were the ingredients that created the unique and disparate recipe for the original IS-F. A recipe that would be enhanced even further in 2010 with the addition of a torsen LSD, reducing the IS-F’s lap time at Car and Driver’s “Lightning Lap” at VIR by 8 and a half seconds and by doing so matching the E92 M3. Yes, you heard that statement correctly, the upstart performance brand matched the all-conquering thoroughbred driving machine that is the E92 M3 on their first car, an absolutely outstanding achievement! Unfortunately, the IS-F sold in such strikingly small numbers that in comparison to the E9X M3, there were approximately 4 times fewer IS-Fs produced. Even more exotic metal such as the Ferrari 458, managed to outsell the Lexus by 9,000 units.
By 2014, the sports saloon landscape had changed once again. F’s German counterparts had been forced to apply the use of turbocharging with downsized engines in comparison to their predecessors due to increasingly stringent emissions and sound regulations. With these steps, the likes of the F82 M4 lost quite a bit of their lustre in terms of the sonority of the powerplant, the character of the engine and linearity of the torque curve. Lexus F however, had other plans… Instead of trailing their peers, F determined that a modified version of the normally aspirated 5.0 litre V8 from the IS-F would be the optimal engine for their new M4 rivalling coupe, the RC-F. The RC-F also introduced a new piece of technology to the performance car landscape, TVD (Torque Vectoring Differential). This system is rather unique as it uses two electric motors on either side of the torsen LSD that help to better distribute the V8’s 467 horsepower between both of the driven wheels at the rear.
On the matter of styling, I believe that the RC-F is one of the only cars on the planet that has managed to pull off complicated design elements without appearing garish and resembling one of the car cast from the original Fast and Furious films, i.e the G82 M4. And if one prefers a more understated, q-car approach to their everyday sportscar, then might I point out the GS-F. A car with a stamp of approval from none other than “his genius”, Jeremy Clarkson for its driving characteristics and V8 soundtrack.
The Lexus F brand really is one of the last bastions of hope for the driver focused performance car. It is clear that as the luxury sportscar evolves, the German counterparts have strayed from the essence of a sportscar, while F has persevered. That essence is not the torque or 0-60 figure, nor the Nurburgring lap time, or even how much downforce the car generates, but rather the character and melodic tones of the engine, the feeling of driver and machine in perfect harmony with the use of Kansei engineering tactics and a purposeful stance without a silly or vulgar appearance. And if the standard car does not meet the demands of the the most hardcore performance car enthusiast, there will always be the route of personalization and fine tuning through the aftermarket.