- 2018 Confirmed
1LT, 2LT: S; deleted for 2019 (GM's official 2019 change list as printed on GM Authority's 2019 changes page); the 2018 guide prints it only as equipment-group contents (the 'Included in Equipment Group' mark only), so the 2018 guide does not date the year
TZD Confirmed
Documented applications
This page aggregates every documented appearance of TZD in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.