Kyle Larson has the fastest practice speed during practice 1 of 185.867 mph for the 2018 NASCAR Cup Series Quaker State 400 by Walmart at Kentucky Speedway.
The practice speeds table shows the fastest lap during practices.
|Driver||From Lap||To Lap||Average Speed|
|Darrell Wallace Jr||10||19||177.433|
Cars must run 10 consecutive laps on the track to be included in this table.