Brazilian Raul Boesel, driving one of Dick Simon's six Indy 500 entries, stole the show from the Mercedes-Benz-powered Penske cars Tuesday with the year's first lap at 230 m.p.h. Boesel ran 230.403 in a Lola-Ford Cosworth.
"I felt Raul had that coming after he ran a 226 in the heat of the day," Simon said. "The way cars were running today, it's a good possibility that (Roberto) Guerrero's record may fall."
Guerrero set the record of 232.482 two years ago in a Buick-powered car.
Penske drivers Paul Tracy, 229.961, and defending champion Emerson Fittipaldi, 229.264, had led before Boesel's run.
Al Unser Jr., Penske's third driver, skipped Sunday's first day of practice to drive 520 miles in a durability test for the new Mercedes engine at Penske's Michigan International Speedway.
"To fully test an engine, you have to run it harder than you ever expect it to be run in a race," Penske said. "With no yellows, and Al running at racing speeds, it had to be tough on the engine and it came out with no problems."