Wheldon tops rain-shortened day 2

But Wheldon wasn't the only driver to offer a glimpse of speed. Helio Castroneves took a run at Wheldon's best lap late in the day coming within a tenth of Wheldon and becoming just the second driver to drop below 40 seconds in two days of practice around the 2.5-mile Indianapolis Motor Speedway oval.

Wheldon's No. 10 Target Chip Ganassi Racing Honda/Dallara was clocked at 39.7543 seconds (226.391 mph) during Wednesday's session the second day of full-field practice in preparation for the 91st Indianapolis 500.

Castroneves later recorded a lap of 225.820 mph in the No. 3 Team Penske Honda/Dallara but Wheldon's best lap was the best of the field for the second day in a row.

"When you have a genuine shot at the pole you have to make sure that mechanically the car is very good for when you take off some downforce," said Wheldon whose lap of 225.074 mph was the fastest during Tuesday's first day. "By the same token I must be getting older because I'm much more concerned with the race than I am the pole."

Castroneves completed 37 laps but didn't put the hammer down until the final minutes of the session. Before his quickest lap Scott Dixon Wheldon's teammate had the second-best time of the day. Afterward Castroneves insisted he wasn't trying to put up a number.

"We're still focusing on our race setup at this point because that's what's really important," Castroneves said. "The fastest car doesn't always win. We improved the car's handling and ended up a little faster than yesterday so we're happy with the direction we're heading."

Dixon held third while Marco Andretti who completed just 11 laps had the fourth-best lap of the day in the No. 26 Andretti Green Racing Honda/Dallara after his dad Michael Andretti did 17 laps in the No. 26 car.

"I didn't think it was bad yesterday so Dad was like 'Let me try it,'" Marco Andretti said. "He had to sweat out all of my problems this morning. He got into it thinking it was going to be good but before he started feeling comfortable he had to make a couple of changes. Based on last year I'm on Cloud Nine but we have a ways to go. I mean look at No. 10."

AGR's Tony Kanaan was fifth Penske's Sam Hornish Jr. sixth and AGR's Dario Franchitti seventh. Vision Racing's Tomas Scheckter was eighth -- the first driver to break up the Ganassi/Penske/AGR stranglehold on speed -- while AGR's Danica Patrick and Panther Racing's Kosuke Matsuura rounded out the top 10.

Because of the long rain delay - cars didn't take to the track until after 4:30 p.m. ET - most drivers didn't get much track time. "We learned a few things about what wasn't quick which sometimes is nearly as beneficial as learning what is quick just so you don't do it again," Patrick said. "I don't think we really did anything today that made us faster."

But Wheldon and his Ganassi crew have been the talk of the Speedway and the season so far. He's led 69 percent of the laps in the first four IndyCar Series races this season but he knows that flat speed is not the only element essential to conquering Indy.

"I learned last year that you can have the car and not win the race," Wheldon said. "Sam dominated the month leading up to the race last year but I think we definitely had a better car. We've got to continue that mindset and not get into that whole scenario where you're throwing away tires to try to get the pole. It's the race that counts."

Practice resumes Thursday at noon ET; pole qualifying is set for Saturday.

Wednesday practice speeds:

Pos  Driver              Speed
 1.  Dan Wheldon         226.391 mph
 2.  Helio Castroneves   225.820 mph
 3.  Scott Dixon         224.902 mph
 4.  Marco Andretti      224.745 mph
 5.  Tony Kanaan         224.112 mph
 6.  Sam Hornish Jr.     224.054 mph
 7.  Dario Franchitti    223.844 mph
 8.  Tomas Scheckter     223.539 mph
 9.  Danica Patrick      223.476 mph
10.  Kosuke Matsuura     223.331 mph
11.  Ed Carpenter        223.090 mph
12.  Scott Sharp         222.798 mph
13.  Buddy Rice          222.696 mph
14.  A.J. Foyt IV        222.655 mph
15.  Ryan Briscoe        222.636 mph
16.  Vitor Meira         222.371 mph
17.  Sarah Fisher        222.241 mph
18.  Michael Andretti    221.814 mph
19.  Davey Hamilton      220.895 mph
20.  Jeff Simmons        219.351 mph
21.  Buddy Lazier        218.847 mph
22.  Milka Duno          218.334 mph
23.  Marty Roth          217.827 mph
24.  Al Unser Jr.        215.407 mph
25.  Darren Manning      129.819 mph