Lexus Engineer Keiichi Yoneda

Lexus Insider Keiichi Yoneda on Driving the IS C, Creating Caribbean Rainstorms, and Making a Vehicle Roof Disappear—Fast

Earlier this year, Lexus released its much-anticipated second convertible, the IS C[1]. Among its many wonders: a roof that retracts in an astounding 20 seconds. Below, Head of Development Keiichi Yoneda, a key mind behind the IS C, tells us about its conception, design, and fastidious testing in some of the world’s toughest climates.

Lexus : Let’s talk driving experience first—how will Lexus owners feel when they take the IS C for a test drive?

Yoneda: I think the IS C offers comfort, superior handling, and a feeling like you’re driving with the wind, through nature. We wanted the car to engage you. To achieve this, we strengthened the body’s frames and we specially tuned the suspension. We also created a superb top-down driving experience by having the vehicle anticipate the driver’s comfort needs. First, we minimized occurrences of turbulent air. This allows drivers to enjoy a comfortable breeze when driving with the top down. Also, the climate control system is designed to automatically maintain the desired cabin temperature, taking into account the amount of sunlight and the car’s speed.

The 20-second roof retraction is the fastest in its class[2]—tell us more about the design.

Video length: 54 seconds

Here, we aimed for “beautiful transfiguration,” which means that we wanted the roof retraction to be speedy, smooth, and quiet. Early prototypes took 25 seconds to open and made some distracting noise. So we carefully observed the movements of all moving parts, then made precise adjustments to eliminate noise and quicken the speed. It was painstaking, but we kept moving the parts over and over again until we had achieved a folding and stretching motion that was graceful.

You also made the vehicle satisfying to look at.

That was the aim, too. Personally, I’m very happy with the car’s overall design form—the elegance you get with a convertible and the sense of unity you get when the roof is closed. To succeed here, we started with a fundamental concept: the creation of a four-seat convertible with zero design compromises.

Did the Lexus SC influence your work?

Yes, notably its elegance. Also its overall quality, such as its world-class level of waterproofing. So we drenched the IS C for 12 hours straight in about five times the volume of water of a Caribbean rainstorm. The waterproofing checks were much stricter than for your average car.

What about heat and cold resistance tests?

We tested it for long periods during the cold winter in Canada—opening and closing the roof while the windows or other parts were frozen, to see what would happen. For heat resistance, we left the IS C outdoors in Arizona for about six months, also opening and closing the roof, as well as driving the vehicle at high speeds. We also tested the IS C in the very humid, hot climate of northern Australia.

How else does the IS C reflect the Lexus ethos?

Video length: 20 seconds

It’s important for a Lexus to have an emotional aspect. I’m a big fan of the GS driving experience, which is a feeling of calm. I also like the sharpness in the handling of an IS. I feel the IS C blends these elements well. With the IS C, I feel I’ve managed to bring in a lot of the instincts and techniques that I’ve acquired throughout my career here. To me, this car is like my child.

Legal Disclaimers

[1] Vehicle with options shown.

[2] Class based on Luxury Coupe, Hardtop Convertible segmentation, retractable hardtop competitors.