Three-time defending IndyCar season champion Dario Franchitti of Scotland still finds it difficult to celebrate his latest title in the wake of English rival Dan Wheldon's death.
But Franchitti has already started working on the new IndyCar chassis set to debut in 2012, a design two-time Indianapolis 500 winner Wheldon was testing just weeks before his death in a crash on October 16 at a race in Las Vegas.
"What happened to Dan was absolutely tragic. We miss him," Franchitti said on Tuesday. "It was very tough. He was a great friend and a terrific competitor. We will all really miss him."
Franchitti won the title after the final race was wiped out following Wheldon's death. The Scotsman's rival for the season title, Australian Will Power, was caught up in the 15-car crash that claimed Wheldon's life.
"We're very proud of this championship. I just don't feel much like celebrating it because of that," Franchitti said.
"Last year was a joy. This year wasn't that."
Franchitti said he has been pleased with the safety push by the US-based open-wheel series in the wake of Wheldon's death, which last week was ruled as caused by a fence pole spearing into the car, causing massive head injuries.
"IndyCar have been working very hard. But it's an ongoing fight with safety," Franchitti said.
"Dan's accident was a catalyst for refueling that effort. Right now I'm happy with what I see and the effort that has been put in and the drivers having been included in that."
Franchitti won the 2007 IndyCar season title, made an ill-fated jump to US stock cars in 2008 and returned to begin his IndyCar title run in 2008. He won four races last year and is already working on the new 2012 chassis design.
Franchitti said he did not feel more pressure going for a fourth title but was able to stay motivated despite success.
"I don't think there's any more pressure," he said. "The trick is to use the experience and keep the motivation. If you can do that you have a good thing going. I'm motivated. I'm ready to do it again."
Part of the motivation is the knowledge of how difficult it is to claim the title every season when so many things can go wrong.
"Each championship has its own shape to it," Franchitti said. "They are fragile things between getting it right and getting it wrong and sometimes it can have nothing to do with anything you've done.
"There are a lot of good drivers and teams that are upset we have been hogging the trophies. It's going to be harder than ever coming back next year."
Chip Ganassi, Franchitti's car owner, says series sponsors are pleased that IndyCar will stage its first race in China next year but that races in China and Brazil are about as much as the series should push beyond North America.
"In terms of China, I think our sponsors feel a race offshore like that, one race is fine, but I don't think we want to start getting three, four, five races outside North America. I think that's going to have a detrimental effect.
"We all have it vivid in our minds the financial crisis of a few years ago in our minds. It makes us a little nervous going forward with plans like that.
"One or two like that are fine for a little bit of cache."

Copyright 2011 AFP American Edition