March 27 2015 Martinsville STP 500 NASCAR Practice #1 Speeds and 10 Lap Averages Ryan Rantz NASCAR News, Practice Speeds 10 Lap Averages, Fastest In practice, Martinsville Practice Speeds, Martinsville STP 500, Martinsville STP 500 NASCAR Practice #1 Speeds, Practice Speeds Martinsville STP 500 NASCAR Practice #1 Speeds and 10 Lap Averages (PDF) More