NASCAR continues to reduce the downforce in its Cup series aerodynamic package.

With a new downforce setup already successfully in place for this season, NASCAR is going even lower this weekend for the Firekeepers Casino 400 at Michigan International Speedway and will do so again in July at Kentucky Speedway.

If the changes meet the approval of drivers, team owners and the sport’s decision makers, they will certainly be included in the 2017 rules package. That announcement would come by Aug. 1.

“I don’t think anyone will have an answer until they drop the green (flag) Sunday,” driver Brad Keselowski said after practicing with the new package Friday. “I don’t think anyone has the real answer. We will all find out.”

NASCAR hopes to keep the momentum going from the low downforce package that was put in place for this season. The less downforce on a car, the freer it handles on the track, bringing drivers’ skills more into play, with an increased potential for passing and more exciting competition.

The potential 2017 package includes further reductions to the car’s spoiler and splitter, in addition to a re-sizing of the rear deck fin to match the spoiler.

“What I’m anticipating is hopefully a lot of slipping and sliding,” said Kurt Busch, who won earlier this week at Pocono and is the Michigan race’s defending champion. “We hope we don’t have a leader that just gets out there and then we’re not able to chase him down. And then the restarts are going to be that much more exciting because of the lack of downforce. How stable will the cars be side-by-side? Nobody knows that yet.”

NASCAR has already made a few tweaks as this season has progressed to further lower downforce (as well as sideforce), including mandating that truck trailing arms must now be welded (put in place for the Kansas race) and the removal of brake cooling fans (the all-star race).

“I enjoy driving the cars more this year with them just being on top of the track more – just sliding around more,” said Martin Truex Jr., who won the Coca-Cola 600 at Charlotte Motor Speedway in May. “We’re having to work a little bit harder in the car and it’s been a lot of fun. We’ve been able to race at most tracks and it’s a bit easier behind cars, get up closer to guys. This is the first time in a few years we’ve been able to kind of get up behind somebody – get close enough to make them loose like you used to do in the old days.

“We obviously still have some challenges at certain tracks and you’re always going to have that just based on tracks all being different.”

One of those “different” tracks would be Michigan, a 2.0-mile oval that was recently repaved and is among NASCAR’s fastest (speeds in practice Saturday exceeded 200 mph). Before this season, drivers had little need for the brake pedal at Michigan with higher downforce, but that’s changed as cars approach the corners with the new aero package.

“When you get that variation in speed, it creates opportunity (to pass),” said Aric Almirola, who drives Richard Petty Motorsports’ No. 43 Ford. “You can drive in the corner a little deeper. You can lift a little sooner. It really opens up a driver’s tool box, if you will.”

As NASCAR has lowered downforce, some teams have tried to put some back in an attempt to regain speed.

“We reduce it and they’re trying to find it,” said Gene Stefanyshyn, NASCAR’s senior vice president of innovation and racing development. “It’s kind of like dieting, right? It’s a constant struggle.”

The struggle continued Friday, when qualifying was delayed by 15 minutes because so many cars failed inspection due to the new rules. It took Truex’s No. 78 Toyota three times to pass.

“There were a lot of failures the first time around,” said Scott Miller, NASCAR’s senior vice president of competition. “As teams do, they always try to get everything they can get and they try to push the envelope.”

This story was originally publishedJune 10, 2016 at 5:08 PM.