"The other problem was, I jumped up there at the front of the line, and I'd lift to let everyone by and they'd all lift," he pointed out. "What do you do? No one wanted to lead."
The new DW12 chassis being used for an oval race for the first time at Indianapolis is definitely having an effect on pack racing on the 2.5-mile speedway, Rahal pointed out: "These things punch such a big hole. It's so easy to get a massive tow. I got behind Tagliani for a few laps and I just didn't have a gear big enough. We thought we were geared too long. For sure, they suck up quite a lot."
But being near the top of the timesheets was still a nice boost for the Ganassi driver, after a quiet first three days at IMS.
"It was great for us, particularly coming off the last couple of day - we felt the car was good all along; we just couldn't figure out where the speed was," he admitted. Part of the problem must have been an engine at the end of its life, which finally let go during Monday's practice: "We put a new Honda engine in it last night, and boom. Pretty pleased with the car today."
Rahal was also looking ahead to the increase in turbo power that the IZOD IndyCar Series organisers were bringing in to spice up the show this weekend, starting on Fast Friday.
"You will be going into the corners 10mph faster, or whatever it's going to be. We expect the boost change to be a 4-5 mph lap average speed difference. That's a lot. That's a big change," he admitted. "Hopefully the handling won't change too much because we've worked hard to get out car where's it's comfortable and fast. But I would think it would be a little bit different.
"I think it's going to be a hell of a race," he added. "More boost, no boost. Whatever. I think there has been great racing this year."
Meanwhile, Sarah Fisher Hartman Racing Indy 500 rookie Josef Newgarden was in 12th place on Tuesday, having been top of the times for two out of the first three days of practice.
"We did more of our own thing today," said the youngster who has impressed everyone on pit road at IMS already this week. "We also got to step through some qualifying stuff, which was good. With limited running, we won't be as high on the time sheets as we have been previous days, but that's fine. We're not going to be the quickest every day. We'll just pick back up tomorrow - we've got a new engine going in tonight."
Simona de Silvestro buoyed the Lotus camp by following Jean Alesi's footsteps and improving the performance of her car by some 10mph over her previous best lap time, after having opted to sit out Monday's track session while HVM Racing sat down and studied the data and worked out the best approach.