Indy Pro Series changes to Sunoco 260 GTXT

Indy Pro Series cars will be fueled by Sunoco 260 GTXT unleaded racing gasoline in 2007, marking a transition from the leaded fuel used previously. Teams completed the season-opening Miami 100 March 24 and almost 8,000 miles of testing using the 98 octane fuel during February's Open Test without difficulty. "We're very pleased with the transition to unleaded fuel," said Indy Pro Series technical director Butch Meyer, who oversaw the change. "We ran all of those miles at the test and numerous miles on the dynamometer, and we haven't seen any change in performance. In fact, in some respects the fuel is much better for certain parts of the engine." The 3.5-liter engines used in Indy Pro Series cars generate approximately 420 horsepower and speeds in excess of 190 mph. "We just took apart an engine that ran 1,700 miles on the unleaded fuel, and it looked perfect," said Jeff Gordon, Indy Pro Series program manager with Speedway Engine Development Inc. "There was none of the typical buildup we saw in the engines when they used leaded fuel." IRL PR