The possible setup changes were explored in a variety of track conditions, including simulated races with single- and double-file starts, solo runs and traditional practice sessions. Gene Stefanyshyn, NASCAR Vice President of Innovation and Racing Development, said that the emphasis of the single-day test was on the intermediate-sized tracks that dominate the NASCAR Sprint Cup Series schedule.
 
"We’re testing quite a wide gamut here," Stefanyshyn said. "We’re looking for basically a fan-centric type of direction. Fans have said they like a lot of passing, they like a lot of side-by-side, they like a lot of lead changes, and so that’s what we’re endeavoring to do."

Michigan was chosen as the site of Monday’s test for a handful of reasons, Stefanyshyn said. Teams have expressed a desire to have a rules package in place by early September, so the timing of Monday’s test fits that window; making the test a part of an extended race weekend helps with cost and efficiency; and NASCAR opted to visit a track that’s not used in the remainder of the 2014 Sprint Cup schedule to avoid giving the 10 teams at the test a competitive advantage.
 
Among the early changes that would be most noticeable to fans were the use of dive planes, fin-like blades in front of the cars’ front fenders. The aerodynamic device is often seen in other forms of motor sports — such as touring cars and sports cars, including in IMSA’s TUDOR United SportsCar Championship — and could potentially help trailing cars in disturbed (or "dirty") air remain more competitive.
 
"Essentially with dive planes, it’s a tool if we talk about the lead car, the lead car creates a wake that the trail car has to drive into, so what the dive planes do — particularly in the low area — they take this wake and really clean it up so that the trail car has a much more predictable balance in the car. …. So it’s really a way to put more predictability into the trail car so he can stay closer."

The middle part of the day was devoted to engine optimization, testing out three different power levels — the current 850 horsepower, then testing in steps down to 800 and 750. Stefanyshyn said the power drops would be emulated Monday through the use of restrictor plates, but that a more formal solution would be in place for 2015 if the change is adopted.
 
A possible decrease in horsepower could combine with a potential rules package that would add aerodynamic drag to the car, which would lower top-end speed at a venue like Michigan, where Jeff Gordon registered a staggeringly fast lap of 206.558 mph — the seventh-fastest qualifying lap in series history — in winning the Coors Light Pole Award on Friday. Stefanyshyn said series officials didn’t have a target speed in mind for the new rules, but that any intent would be to promote better racing.
 
"There’s no denying the fact that our speeds have picked up and that marches hand in hand with the power as it’s developed over the years, and so we look at the cars essentially in our form, race cars that look like passenger cars, right?" he said. "They’ve somewhat changed in shape, they somewhat mirror what the manufacturers are doing, and the power has crept up. So we think by looking at this issue and being open-minded to investigate it, we believe we’ll make the racing better, but we’ll also deal with this speed issue which has been continuing to creep up and up."

The latter part of the day was scheduled to explore the option of giving drivers the ability to adjust their car mid-race, thereby altering the car’s handling characteristics. Such a change would break ground for NASCAR, which has historically not adopted the in-car driver aids used in other forms of motorsports.
 
"We’ve been somewhat hesitant to throw all kinds of adjustability on the car. We like kind of the pure, historic form of our racing, so we march very cautiously here, careful as we do these things," Stefanyshyn said. "Our thinking is we allow them to change things in the pits, so now we’re going to investigate whether giving that control to the driver so that he can bring his car into better trim if he’s not set up right. … There’s a technical piece of it, but then there’s the human piece of it in the drivers and how well they feel comfortable with it and that type of thing. This is something that we need to ask them for their opinions on that."

Gordon, who backed up his blazing speed with his third victory of the season in Sunday’s Pure Michigan 400, said before the race that the opportunity to make in-race adjustments from the cockpit was an enticing one.
 
"I think it’s sort of a reaction to the change we have," Gordon said. "We have so much of a change in traffic behind other cars. The balance changes so much that we’re trying to figure out how we can adjust that balance when we get behind cars and then to help passing and make the races more exciting and more competitive than they already are. And that’s a step toward that. So, that would be great. I’d love to know how much adjustment you’re going to get.
 
"I always go back to adjustments that I used to have in open-wheel cars and I used to dial myself right out of being competitive," Gordon added with a laugh. "So, I want to make sure they don’t allow me to have too much adjustment or if they do, I’m going to make sure the team tells me how far I can go with it."
 
A handful of teams had issues early on. Matt Kenseth missed a shift, leading to engine failure in the Joe Gibbs Racing No. 20 Toyota, Danica Patrick brushed the wall with her Stewart-Haas Racing No. 10 Chevrolet, and Jamie McMurray was briefly in and out of the garage with a mechanical issue on the Chip Ganassi Racing No. 1 Chevy.

Patrick said her early test runs with different rear gearing and aero alterations didn’t produce dramatic changes, with only slightly slower speeds and improved drivability with a higher-downforce package. She said she was eager to sample more of the potential enhancements in traffic before the day’s end.
 
"There are two ends of the spectrum that work — speedway style, flat-out, and easy to drive — but I don’t think it’s fair to have all the racing like that," Patrick said. "It’s entertaining at speedways, but we need tracks that are dedicated to getting the car really fast. Tracks like Atlanta, Homestead where you slide around a lot, it makes for passing, too. I think we need to figure out how to make the cars transition from beginning to end of run. That creates passing."

The full list of drivers and teams involved in the test:
 
— Aric Almirola (Richard Petty Motorsports No. 43 Ford)
— Denny Hamlin (Joe Gibbs Racing No. 11 Toyota)
— Kasey Kahne (Hendrick Motorsports No. 5 Chevrolet)
— Matt Kenseth (Joe Gibbs Racing No. 20 Toyota)
— Brad Keselowski (Team Penske No. 2 Ford)
— Jamie McMurray (Chip Ganassi Racing with Felix Sabates No. 1 Chevrolet)
— Paul Menard (Richard Childress Racing No. 27 Chevrolet)
— Danica Patrick (Stewart-Haas Racing No. 10 Chevrolet)
— Ricky Stenhouse Jr. (Roush Fenway Racing No. 17 Ford)
— Brian Vickers (Michael Waltrip Racing No. 66 Toyota)