Franchitti, the defending champion, posted the best practice lap Friday of one minute 0.2786 seconds to set the pace as he tries to captures his fourth victory at Exhibition Place.
He'll have a much better shot at it than Hinchcliffe or Tagliani, who were both charged with 10-grid spot penalties for changing their engines. Tagliani, from Lachenaie, Que., posted the 11th best practice of 1:00.9297, but that will mean little when he ends up 10 positions lower than wherever he qualifies on Saturday.
Hinchcliffe, from Oakville, Ont., never even completed a lap after his car was hampered by mechanical issues.
"Certainly it makes for a more challenging weekend than we wanted, but at the end of the day it's still possible for the Go Daddy car to move forward," said Hinchcliffe. "Last time we got an engine penalty we were able to come back and finished on the podium. So we may be down but we're certainly not out."
Franchitti downplayed any early assumptions he had another victory in the bag ahead of Sunday's race. Instead the Scottish driver, who is second in career wins in Toronto behind only Michael Andretti's seven, said he was just happy to return to a track where he feels comfortable.
"It's always good to come back to a place you've enjoyed success, but whether you've enjoyed success or you've had a bad history you've still got to treat it the same and try and win there," said Franchitti.
"There's tracks five years ago I never thought I would have won at that I have, so you just got to have an open mind. But I do, I love coming back to Toronto, for the track and also the town as well. It's one of my favourite stops on the circuit."
Franchitti was followed by Simon Pagenaud, who had the second best lap at 1:00.3904, while Scott Dixon followed in third at 1:00.5423, giving them good starts going into Saturday's qualifying session at the 11-turn, 2.824-kilometre street course.
The practice had a scary start after Justin Wilson's car crashed into Sebastien Bourdais' pit, injuring four crew members. Chuck Homan and Raffi Aroyan were taken to a hospital after Wilson's car failed to stop, pinning Homan's leg between two cars and injuring Aroyan's ankle.
Two other crew members, Dragon Racing's Daniel Martin and Michael Cole, a member of Wilson's Dale Coyne Racing team, were treated at the track, while Homan and Aroyan went to hospital but were later released.
Wilson, who finished fourth in practice, blamed a faulty transmission for the accident, and said in a statement posted on his website that he was stuck in first gear and couldn't change to neutral. He added cold brakes also contributed to the accident.
"At the last second I tried to dive into the wall to take the speed off, but those guys were there and had no idea I was coming," Wilson said. "I really hope they are OK."
It was a steamy day at the track, with temperatures reaching 35 C that kept the bleachers bare despite attendance being free. Franchitti, who spoke with sweat running down his face, said the heat wasn't a factor on the drivers nor did it have any effect on the practice times.
"I don't think it's that much warmer than what the people in the stands are experiencing. You know it's pretty warm in those metal bleachers," he said. "But I think to do it for two hours on Sunday would be pretty intense."
Notes: Simona de Silvestro was also assessed a 10-grid spot penalty for changing out an engine before it reached its mileage limit. The penalty is especially costly for De Silvestro, who will also receive the penalty at the Edmonton Indy in two weeks after her team fit its sixth engine of the season. The limit is five. ... France's Tristan Vautier had the fastest practice time in IndyLights at 1:04.7297. David Ostella of Maple, Ont., finished ninth at 1:05.5903.