In his first run at the Indianapolis Motor Speedway since the 1995 Indy 500, Bryan Herta strapped into Dario Franchitti's regular #27T Archipelago/Motorola Dallara-Honda and posted a best speed of 225.380mph (39.9326secs) in 53 laps around the 2.5-mile Brickyard.

Herta used the fourth day of official Indy 500 practice session to familiarise himself with the IRL IndyCar Series car he will be running at Texas Motor Speedway and Pikes Peak International Raceway this June. Herta is the team's back-up driver for the 500 in the event that a rain delay forces first choice driver Robby Gordon to leave Indianapolis for the NASCAR race in Charlotte, but will replace the injured Franchitti at the following two IRL rounds.

"From my perspective, today went perfectly," the two-time CART race winner reported, "I was able to get comfortable in the Archipelago/Motorola car and run flat out.

"We started out with a lot of downforce and then trimmed it out a little. I was able to give the team some feedback so I felt like I could contribute some on the set-up as well. I needed to run some laps at Indy because, if something happened with the weather and Robby couldn't start or couldn't finish the race, you don't want to jump in here without having had some laps."

After Herta's exploratory outing, in which he trailed former Indy 500 winner Kenny Brack's ultimate pace of 231.0390mph, Gordon will return to the cockpit tomorrow to continue practicing for the 87th running of the Indianapolis 500. The CART regular turned NASCAR frontrunner has been posting increasingly quick times during the week, as he builds up towards the first leg of another 'double' combining the 500 and the Winston Cup Coca-Cola 600 at Charlotte.

Herta's next appearance behind the wheel of the Archipelago/Motorola entry will be on Monday 12 May, in a test session at Pikes Peak.

"We had a chance to get Bryan in the car today because Robby had another commitment," explained Archipelago/Motorola team manager Kyle Moyer of the decision to run Herta, "It was good to get Bryan in the car and get him comfortable so that, when we go to Pikes Peak next week to test, we can get right into our programme. Plus, he hasn't been in a car like this for a while, so it allowed him to get comfortable. In the long run, I'm sure this is going to prove to be a good choice."