GTR

GTR, a TLA, can refer to:

Gran Turismo Racer, Gran Tourer Racing or similar, used on sports cars such as Ultima GTR and Nissan Skyline GT-R.
GTR - FIA GT Racing Game, which is developed by Simbin.
GTR (band) founded by guitarists Steve Hackett and Steve Howe
Substitution model - The generalised time reversible substitution model
Grand Trunk Railway
Golden Triangle Regional Airport, Lowndes County, Mississippi
General Theory of Relativity, same as general relativity, abbreviated GR.
In D.I.C.E., this is an acknowledgement response used by D.I.C.E. members, which is similar to FAB in Thunderbirds (TV series).