Toyota engine codes are typically formed in two sections, each separated by a dash. The first section, before the dash, represents the particular engine family, while the section after the dash represents the engines particular attributes and features.
Engine Family: The first number represents the revision of the particular engine block, where a larger number indicates a newer revision. The letter(s) following this number indicate a particular block family, bore, and stroke.
Engine Attributes and Features: Each letter represents an indicative feature of the engine.
G = Wide angle, twin cam head ("sporty version")
F = Narrow angle, twin cam head ("economical" version)
T = Turbocharged
Z = Supercharged
E = Fuel Injection
U = Japan Emission package
C = California Emission package