Following six days of practice totaling 35 sun-splashed hours on the Indianapolis Motor Speedway, it's time for teams to literally switch gears.

IndyCar has approved an increase in the turbocharger boost level for "Fast Friday" on May 18 and the May 19-20 time trials for the Indianapolis 500 from 130 kPa (kilopascals) to 140 kPa. The increase will add 40-50 horsepower to the 2.2-lter, turbocharged V-6 engines supplied by Chevrolet, Honda and Lotus, resulting in an increase of 4-5mph per lap. The boost level will be returned to 130 kPa for the 200-lap race May 27.

Teams/drivers continued to work on race set-ups and simulations May 17 (the session was delayed an hour at the start for Katherine Legge to start her Rookie Orientation Program).

Scott Dixon, the 2008 race winner, was quickest on the day with a lap of 40.3428 seconds (223.088mph; second-quickest of the month) in the No. 9 Target Chip Ganassi Racing car.

Josef Newgarden, who was quickest a day earlier, was second on the speed chart (40.1115 seconds, 222.709mph) in the No. 67 Sarah Fisher Hartman/Dollar General car. Graham Rahal jumped to third late in the session with a month-best 222.080mph, and IZOD IndyCar Series championship points leader Will Power (221.932) was fourth. Justin Wilson finished fifth at 221.715.

Twenty-nine drivers recorded 1,391 laps without incident.The 2.5-mile oval is open for practice from noon-6 p.m. May 18, with Pole Day qualifying featuring the top-nine shootout commencing at noon May 19.

Pos  Driver               Team/Car                      Speed
1.   Scott Dixon          Ganassi DW12-Honda            223.088
2.   Josef Newgarden      Fisher DW12-Honda             222.709
3.   Graham Rahal         Ganassi DW12-Honda            222.080
4.   Will Power           Penske DW12-Chevrolet         221.932
5.   Justin Wilson        Coyne DW12-Honda              221.715
6.   Ryan Briscoe         Penske DW12-Chevrolet         221.510
7.   Wade Cunningham      Foyt DW12-Honda               221.450
8.   Dario Franchitti     Ganassi DW12-Honda            221.344
9.   Charlie Kimball      Ganassi DW12-Honda            221.321
10.  JR Hildebrand        Panther DW12-Chevrolet        221.022
11.  Mike Conway          Foyt DW12-Honda               220.900
12.  Alex Tagliani        BHA DW12-Honda                220.695
13.  Oriol Servia         Panther/DRR DW12-Chevrolet    220.643
14.  Helio Castroneves    Penske DW12-Chevrolet         220.598
15.  Bryan Clauson        Fisher DW12-Honda             220.489
16.  Tony Kanaan          (#11) KV DW12-Chevrolet       220.167
17.  Takuma Sato          Rahal DW12-Honda              219.900
18.  James Jakes          Coyne DW12-Honda              219.826
19.  Ana Beatriz          Andretti DW12-Chevrolet       219.604
20.  Rubens Barrichello   KV DW12-Chevrolet             219.432
21.  Michel Jourdain Jr.  Rahal DW12-Honda              219.152
22.  Ed Carpenter         Carpenter DW12-Chevrolet      219.095
23.  EJ Viso              KV DW12-Chevrolet             218.550
24.  Townsend Bell        Schmidt DW12-Honda            218.528
25.  Sebastien Bourdais   Dragon DW12-Chevrolet         214.715
26.  Tony Kanaan          (#5) KV DW12-Chevrolet        214.422
27.  Jean Alesi           Fan Force DW12-Lotus          207.489
28.  Simona de Silvestro  HVM DW12-Lotus                205.690