Fog remained a factor for what turned into be just a 20 minute practice when rain came and halted cars from working on qualifying setup. 28 cars participated in practice, so if qualifying is rained out in the afternoon the starting lineup will be set by owner standings.
Carl Edwards posted the fastest single lap speed at 179.802 mph, which was over one mph faster than Kevin Harvick, who recorded the second fastest lap. If rain cancels qualifying, the No. 4 Chevrolet would start from the pole on Sunday.
Last year's pole-sitter for this event, Kurt Busch was third on the leader board at 178.649 mph. Paul Menard was fourth at 178.250 mph and defending Cup Series champion Kyle Busch rounded out the top five.
Jimmie Johnson, Casey Mears, Joey Logano, Greg Bffle and Tony Stewart rounded out the top 10.
Three drivers were tied for most laps ran in the practice session at seven. Cup Series rookie Chris Buescher led the way in that category at 23rd. Michael Annett and Brian Scott also completed seven laps and were the two slowest cars on one lap speed.
Notable drivers who didn't complete a lap were August winner, Matt Kenseth, Ryan Newman and Austin Dillon.
Qualifying is set to role at 4:15 p.m. ET if rain moves out of the Pocono Mountains.
Much like all season long, Joe Gibbs Racing was quick on track in preparation for the main event. In the first session it was Kyle Busch who was quickest.
Busch was the fast car out on track in the opening practice Saturday morning. The No. 18 laid down an early lap of 157.839 mph, which is just less than eight mph slower than the quick time on Friday.
Two of his JGR teammates were right behind him on speed. Denny Hamlin posted an early lap of 157.356 mph. Carl Edwards was third at 157.006 mph, just over a tenth of a second off the fast lap.
Ryan Newman was fourth in the session at 156.770 mph and Kurt Busch rounded out the top five 156.590 mph.
Pole-sitter, Kevin Harvick was 10th fastest in the session at 156.413 mph. The No. 4 team dominated the race in the fall leading 355 of the 400 laps.
10-time Dover winner, Jimmie Johnson was 12th on the board, while his Hendrick Motorsports teammate, Chase Elliott was eighth, quickest of all the rookie drivers.
The fourth JGR driver, Matt Kenseth recorded the 19th best time. He was just over three-tenths of a second off the top time. After being involved in a big practice crash on Friday, Danica Patrick led the way of drivers in backup cars with the 25th quickest time. Jamie McMurray was just behind in 26th and Tony Stewart was mired down in 34th.
Hamlin led the way at a lap of 157.329 mph. In the past Dover has been the Achilles heel for the No. 11 team, but he has been fast all weekend long.
Harvick rebounded from the first practice to lay down the second quickest lap in the second session. He ran a speed of 156.447 mph which was over a tenth of a second behind the hot lap that Hamlin put down.
The younger Busch brother was third fast at 156.365 mph, with his older brother in fourth at 155.777 mph. Elliott rounded out the top five on the board at 155.696 mph.
Kenseth improved on the morning session and went to eighth in race conditions.
Dale Earnhardt, Jr. was down to 25th on the leader board. The No. 88 car will start on the outside of the front row when the green flag waves, but struggled Saturday in race conditions.
McMurray ran 62 laps in the session, most out of the 39 drivers that completed a lap. The No. 1 machine struggled in his backup car prior to this practice that he ended in 17th.
The last time NASCAR was at the Monster Mile, McMurray finished fourth at Dover and finished one position shy of making it into the next round of the Chase.
The green flag will wave shortly after 1:00 p.m. on Sunday. Johnson is the defending winner of the event.
The last time the Cup Series ran at Dover, Harvick led 355 laps en route to securing a Chase birth into the second round of the Chase. On Friday, it was a lap of 165.145 mph that secured the pole for the No. 4 car. Had that lap been ran in qualifying it would have set a new track record.
"That definitely changes your approach," Harvick said of the possibility of rain. "That's what the forecast looked like all week and we just decided to come with qualifying trim."
Dale Earnhardt, Jr. will line up second after having one of his better practices of the year. At a lap of 164.707 mph it will be his best start since he was awarded the pole at Daytona last summer. The qualifying for that event was also postponed due to rain.
"Hopefully we can get some practice in tomorrow and work on the race setup a bit," said Earnhardt.
The Joe Gibbs Racing duo of Kyle Busch and Carl Edwards will start alongside in Row 2. Each driver has a victory on the concrete at Dover and both have already clinched a spot in the Chase this season.
Ricky Stenhouse, Jr. will round out the top five, running a lap in practice at 163.815 mph.
The other two JGR cars will lineup inside of the top 10, Denny Hamlin in sixth and Matt Kenseth in 10th.
Chase Elliott is the highest starting rookie in 13th. While fellow Rookie of the Year competitor Brian Scott was the only driver to make a race run in practice. He will start 17th on Sunday.
10-time Dover winner, Jimmie Johnson will start from 21st, with Joey Logano alongside in 22nd. Other notable drivers starting toward the rear are Jamie McMurray 24th, Danica Patrick 31st and Tony Stewart 34th.
There are two practice sessions on Saturday to prepare for the AAA 400 Drive for Autism. Johnson is the defending winner of the event.
The last time the Cup Series raced at Dover it was Harvick that dominated the race leading a career-high 355 laps, racing his way into the next round of the Chase. If this were qualifying, the No. 4 machine would have set a new track record.
Dale Earnhardt, Jr. ran the second quickest lap at 164.707 mph. With just six laps run on the racetrack, the No. 88 car was focused primarily on qualifying runs with rain on the horizon.
A pair of Joe Gibbs Racing teammates slotted themselves in third and fourth. Kyle Busch ran at 164.489 mph and Carl Edwards at 164.144 mph. Ricky Stenhouse, Jr. rounded out the top five at 163.815 mph.
Outside of the first five minutes with a wreck involving the Stewart-Haas Racing teammates of Danica Patrick and Tony Stewart, along with Jamie McMurray the practice went green. All three of those drivers got back out on track in their backup cars, with the No 1 quickest at 24th.
Chase Elliott was the fastest rookie driver in 13th, just under three tenths of a second behind the lap that Harvick put down. His teammate, and 10-time Dover winner, Jimmie Johnson, was 21at on the chart.
If the rain stats away from the racetrack, ualifying is slated fto begin at 3:45 p.m.
After just a handful of minutes passed in Sprint Cup Series opening practice, Danica Patrick had a rear gear failure down the frontstretch that involved her owner Tony Stewart as well as Jamie McMurray.
The No. 10 machine laid down a ton of oil on the racetrack that took over a half hour to cleanup. At the moment of caution she had the 16th quickest time.
“I just got back to the throttle and lost power to the engine and it spun sideways,” Patrick said. “There’s a lot of oil all over the racetrack with corner workers slipping all over it. Big mess and hope we can go green again. It’s bad for me, bad for Tony, bad for Jamie and everyone not being able to practice.”
The No. 14 Chevrolet was eighth when getting involved in the incident and it was Stewart’s first incident since climbing back into the racecar last month. He was running behind Patrick and slid in her oil crashing the right front into the concrete wall, coming down into the inside wall.
A third Stewart-Haas Racing driver, Kurt Busch, felt a miss in his rear gear, but caught it in time and brought his machine into the garage after posting the ninth quickest time.
“I was feeling something all along with the rear gear on the drive train, Busch said. “There was something weird so I came in.”
The rear gear that the Stewart-Haas Racing team is having has been used at other tracks. This is the first time that the team has experienced issues with this particular gear.
“All of the cars have the same gear from the same manufacture with the same material,” said competition director of SHR Greg Zipadelli. “We will be fine. It’s tough losing two cars, but it’s just part of this sport.
McMurray was running just behind the two cars and as he went to slow his car down was caught up in the incident. While leaving the infield care center he was holding an ice pack on his right elbow. The team believes that he banged it against the seat.