The implementation of amorphous carbon coatings has emerged as an effective approach to combat tribological degradation in methanol fuel injection systems, where conventional coating materials suffer accelerated wear under boundary lubrication regimes. This study provides the first comparison of four amorphous carbon specimen-tetrahedral amorphous carbon (ta-C), graphite-like carbon (GLC), soft hydrogenated amorphous carbon (soft a-C:H), and tungsten carbide-reinforced amorphous carbon (WC/a-C:H)-paired with SUS304 counterpart in methanol environments. The ta-C/SUS304 tribopair exhibits superior tribological performance with a low friction coefficient of 0.12 and a wear rate of 3.2 × 10 −7 mm 3/(N·m) compared to other three coatings. In contrast, soft a-C:H coatings display catastrophic delamination. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) reveals tribo-oxidation dominates the wearing process, where methanol molecule interacts with amorphous carbon surface governed by tribochemistry. Specifically, ta-C has a mechanically robust sp 3-dominated matrix that resists abrasion and minimizes corrosive wear in methanol. This study helps to understand how hydrogenated and non‑hydrogenated amorphous carbon react with methanol during friction by clarifying the superficial chemistry through multiple characterizations, which provides the practical guidelines for designing extremely durable coatings for the moving components in methanol-fueled systems.