Dale Earnhardt Jr. tops eighth and final Daytona 500 practice

Most of the small packs were made up of teammates or cars that had some kind of relationship. On the top of the charts sat the No. 88 Hendrick Motorsports Chevrolet, who put down a fast lap of 197.131mph.

"Surface of the track seems to be getting down on grip, which is a good thing," Dale Earnhardt Jr. told MRN Radio after running several laps by himself. "I expect there to be more of that on Sunday."

Early in the session, a multicultural pack formed with Clint Bowyer, Greg Biffle, Trevor Bayne, Chris Buescher, David Ragan, and Robert Richardson Jr. That was the largest drafting group over the 1 hour and 40 minute practice.

Shake-down session

Biffle's went out for the same reason many drivers went out today: To shake-down their 500 engines. "We needed to check for leaks, make sure the temperatures are correct and give the guys a chance to check everything over. No vibrations."

Things were not status quo for Matt Kenseth though, who continued to battle an unknown vibration in his backup car that crew chief Jason Ratcliff has been unable to pinpoint. But by the end of the session, the vibration was gone and the No. 20 team focused on radio checks.

Drafting with your friends

The Penske duo of Brad Keselowski and Joey Logano, as well as the affiliated Wood Brothers Ford of Ryan Blaney ran together for 29 laps each, more than any other driver with the exception of Kenseth. The trio ended practice second, third and fourth on the speed charts behind the No. 88.

Another pack of note was the Hendrick-powered group that included Kevin Harvick, Kurt Busch, Brian Vickers, Clint Bowyer, and pole-sitter Chase Elliott.

"Definitely going to have to adjust. It's on the ground too much," radioed Harvick after drafting for 10 laps.

"Alright guys, let's get ready to win the 500," said the No. 41 team after concluding their running for the day.

The Hendrick duo of Jimmie Johnson and Kasey Kahne experimented one another for a handful of laps in the draft. Afterwards, Kahne was instructed to practice his pit entry, exit and stopping in his box.

"It's drafted pretty well all week," Kahne said after getting out the car. "We had work on handling. After the 150, I was very loose. We worked on that yesterday and I feel like we've gotten a handle on things."

15 cars did not practice, including drivers of note Kyle Busch, Carl Edwards, Denny Hamlin, Martin Truex Jr. and Austin Dillon.

Of the ten drivers who ran ten consecutive laps, Elliott was quickest with an average speed of 195.106mph.