Key figures split over rules package for IndyCar's Phoenix return

IndyCar used the one-mile Arizona track for pre-season testing last week, and will race there for the first time since 2005 next month.

Andretti Autosport team owner Michael Andretti believes the test showed more downforce is required to ensure adequate overtaking.

"We're not going to make a good show if we go with the downforce they have currently, so that's why we're pushing for more downforce for the race," he said.

"People will say we're pushing for that because we think we have an advantage. But no, we as a series just can't afford to screw up this race."

Downforce levels were already high for the test, where frontrunners were averaging 190mph laps, and reigning champion Scott Dixon believes going higher still would be the wrong move.

"We need to have the ability for the good cars and packages to get away from those that are not so good," said Dixon.

"The problem with more downforce is it gets too easy. It would be a mini 'pack race'."

He thinks the package used for the test should be retained.

"You could go down a different road of taking downforce away and having a softer tyre but it's pretty late in the game to do that," Dixon said.

"Where we are starting right now will be a pretty good race. Will it be hard to pass? Yes, but I think it is going to be possible."

But he admitted the alterations to the track since IndyCar's last appearance had potentially made overtaking tougher.

"This track has changed a lot," Dixon said. "It's been NASCAR-ified. There is more banking and smoother pavement.

"This track used to be quite fun because of Turn 2. It closed on itself and made it hard. [Now] once you get through the middle it's an easy exit.

"Back in the day if you had a really good car that could finish the rest of the corner you would get a great run down the backstraight."

Will Power suggested existing downforce levels were already going to make the race an incredible physical challenge.

"I don't think it will be possible to do an entire race physically all green, but we'll see," he said.

"It's the most downforce any open-wheel car has ever had. It's the most downforce ever run on an oval. That's why it's physical. It's insane the number that it is."

Juan Pablo Montoya believes frontrunners may have to rely on traffic for overtaking chances.

"By yourself it's going to be very hard to pass, but I think because it's so fast the traffic is going to be a key thing," Montoya said.

"Whoever nails whatever you need for this traffic is going to be the guy that's going to win this."