Graham Rahal led the charge with a cumulative 18 positions advanced in the Shell and Pennzoil Grand Prix of Houston doubleheader Oct. 5-6.

Sebastian Saavedra gained a total of 17 positions, while Sebastien Bourdais and Josef Newgarden also were big movers with 14 positions gained during the 90-lap races on the 1.634-mile, 10-turn course.

Rahal's seventh place in Race 1 after starting 24th because of grid spot penalty for an unapproved engine change in the No. 15 blu eCigs car for Rahal Letterman Lanigan Racing was his best finish since placing fifth at Pocono Raceway in July and his highest on a street course since finishing second at Long Beach in April.

"The blu e Cigs guys did a great job making the right decisions in the race," Rahal said. "Neil (Fife, race engineer), Wayne (Gross, assistant engineer) and everybody who made the tweaks to this thing went in the right direction. To go from 24th to seventh is always a good day."

In Race 2, contact on Lap 1 forced Rahal to pit for a front wing assembly swap, which put him a lap down. He finished 18th after starting 19th as the lineup was set by entrant points because the morning 30-minute qualifying session was washed out by rain.

Rahal's first Indy car race in Houston came in Round 3 of the Champ Car World Series on April 22, 2007, and he became the youngest driver (18 years, 3 months, 18 days) to earn a Champ Car podium with a runner-up finish to Newman/Haas/Lanigan Racing teammate Bourdais. Rahal missed his high school prom to compete.

Saavedra, driving the No. 6 Dragon Racing car, gained 12 positions in Race 2 to finish 12th. He advanced five spots relative to his starting position to finish 14th in Race 1.

"We took advantage of absolutely everything we could. Starting last and finishing 12th took a great job from everybody," he said. "We had great pit stops. However, our strategy didn't go as planned but we still gave a good battle. We had a strong car and we were battling up front."

Teammate Bourdais finished eighth and fifth in the No. 7 Dragon Racing entry. He's recorded top-five finishes, including three podiums, in the past five street course races.

After advancing 13 spots in Race 1 to earn his fourth top five of the season, Newgarden finished 13th in Race 2 in the No. 67 Sarah Fisher Hartman Racing car with primary sponsorship from Texas-based Strike.

"Overall, the Strike car was incredible this weekend," he said. All of the people from Strike were so supportive. We can do a great job for them in the future and I think it would be incredible to represent them again. I'm really glad that we had a great finish for them in Race 1."

Oriol Servia was the biggest mover in Race 2 with 14 positions gained to finish seventh in the No. 4 National Guard Panther Racing car.