Three-time NASCAR champion Tony Stewart says he will retire after 2016 seasonKANNAPOLIS, N.C. (AP) Three-time NASCAR champion Tony Stewart says he will retire after 2016 season.SI Staff|Share on FacebookShare on XAdd us as a preferred sourceKANNAPOLIS, N.C. (AP) Three-time NASCAR champion Tony Stewart says he will retire after 2016 season.Add us as a preferred source on GoogleFollowLoading recommendations... Please wait while we load personalized content recommendationsPublished Sep 30, 2015 | Modified Sep 30, 2015SI STAFFShare on FacebookShare on XHome/Racing