(Interview with Takuma Sato) Maximum Velocity of Over 380km/h! Importance of Tires in the IndyCar Series, One of the Fastest Motor Races in the World

We had an interview with Takuma Sato, a racing driver, about the Verizon IndyCar® Series at the Bridgestone booth at the Tokyo Motor Show 2017.
Sato talked about tires, the most important factor in the fastest round race with the average velocity of 360km/h, in front of the tires which he actually raced on when wining the Indy 500.

This article is the translation of the interview held in Japanese with supplemental information.

Takuma Sato (Sato): Hello. Thank you for inviting me today.

Moderator: First off, I would like to congratulate you on your victory at the Indy 500 (the Indianapolis 500-Mile Race).

Sato: Thank you.

Moderator: This season's IndyCar Series is over now, but are you still very busy even in the off-season?

Sato: Yes, I'm invited to many events, so I travel back and forth between the US and Japan. But since everyone congratulates me as the champion of the Indy 500 in every event, I'm busy but happy as well.

Moderator: You are here at Bridgestone's booth at the Tokyo Motor Show today. What does the Indy 500 victory mean to you?

Sato: Each victory of any race makes me happy, and is special for me. But I didn't expect to win the Indy 500, so I'm extremely delighted. The Indy 500 holds a significant position for me.

Moderator: Only with technique or luck, can you win such special race? Even with technique and luck, it is not easy to win this special race. Several years ago, you almost scored the first podium finish, didn't you?

Sato: Yes, on the final lap, I was racing with Dario Franchitti for the championship, and would have won the race if I had taken three more corners. But because I couldn't make it at that race, I could truly understand what winning the Indy 500 means, so I learned from the failure. Five years have passed since that race, and everything was set ready for the victory this year, so I finally achieved the championship.

Moderator: I see. Has your life changed after becoming the champion of the Indy 500?

Sato: Yes, it has changed. I have events almost every month, and will be celebrated as this year's champion until the final round of the Indy 500 starts next year. Moreover, I'll be introduced as the champion of the Indy 500 for the rest of my life. Every time I'm invited to events in the US as well as in Japan, I’m celebrated there. It's the special power that only the Indy 500 possesses.

Moderator: Sounds like you are the man who has reached the American dream. In the Indy 500, drivers race for a distance of 500 miles (about 800km), and the average velocity is as fast as 360km/h.

Sato: Normally, going even straight in excess of 300km/h is such flashes of speed. But when the average velocity per lap is 360km/h, the speed reaches about 350km/h when cornering and over 380km/h along a straight end of a circuit. This indicates the Indy 500 is the fastest round race in the world.

Moderator: So without total reliability of a driver, a team and tires, it's impossible to win, but tires are regarded as one of the important factors, aren't they?

Sato: Yes, tires are one of the most important factors.

Moderator: Bridgestone provides tires of the Firestone brand in the IndyCar Series, and the tires which Takuma used in the race are on exhibit at this booth today.

Sato: This is the one I raced on when I won the Indy 500.

Moderator: The tire contact patch is so severely worn out.

Sato: When in contact with the road surface, the tire rubber is heated and grips the asphalt. That is how the grip power is strengthened. A race tire is very sensitive to temperature, but gives more grip by being heated, so the tire surface looks like it is burnt out after a race. But this tire picks up pieces of scrap rubbers of worn tires which are dropped on a race course, so it makes the tire surface rough. Rightafter the race and we return from the course, the rubber is heated, and the surface looks stickier than it does now.

Moderator: What is a major difference from passenger car tires?

Sato: passenger car tires need to adjust to many environments such as cold, warm, sunny and rainy days. So they have to perform under a full range of conditions, but this Firestone tire for the Indy 500 is made to exhibit its strength at the speed of 350km/h on a superspeedway. Temperature control is essential in a race, and how to monitor four wheels in front, rear, right and left, and how to set them is considered a strategy.

Moderator: So do you also hold a meeting with Firestone staff for a race?

Sato: Yes. I'm not involved in the tire development itself, but engineers, teams and drivers have to place the primary importance on how to make best use of tires we are provided with. Immediately after tires are replaced with new ones, grip is strong, but its performance changes as a race goes on. So we take driving and setting measures against it. We make nearly seven pit stops to change tires during the Indy 500 race with the driving distance of 800km. This shows how important tires are.

Moderator: Just looking at these tires gives us a glimpse of how the race went on.

Takuma Sato's Profile
Making the complete switch from bicycle racing in which he engaged as a student, Takuma Sato entered racing school at the age of 20 to join the world of motorsports. He made his way into Formula One in 2002, and finished on the podium at the United States Grand Prix in 2004. In 2010, Sato moved to the IndyCar Series, and became the first Japanese winner of the Grand Prix of Long Beach in 2013. He is also the only Japanese driver who made it to the podium in both F1, and IndyCar races. Furthermore, he also won the Indy 500 - one of the three largest races in the world - in 2017.

⇒the latter part（With Hélio Castroneves!）