This study investigates the impact of Augmented Reality (AR) on motivation and cognitive load in an engineering drawing (ED) course, comparing traditional teaching methods with three AR modalities: marker-based, markerless, and web-based. A total of 140 undergraduate engineering students participated, divided into a control group and three experimental groups, each using a different AR application. The instructional materials motivation survey (IMMS) assessed motivation across four constructs: attention, relevance, confidence, and satisfaction. The results indicate that while traditional methods maintained higher attention, AR applications significantly enhanced relevance, confidence, and satisfaction. Specifically, marker-based AR showed strong spatial engagement by providing tangible interactions with virtual objects, aiding in the comprehension of complex engineering drawings through hands-on manipulation. Markerless AR offered seamless integration, allowing students to interact with virtual elements without needing physical markers, facilitating a more fluid learning process. Web-based AR ensured accessibility, enabling students to access AR content from any location with an internet connection, supporting flexible and remote learning. The study revealed that AR in ED courses can significantly improve learning experiences by making content more relevant, boosting student confidence, and increasing satisfaction. The findings also suggest that integrating AR in ED courses can create more effective and engaging learning environments. The positive impacts on motivation and cognitive load underscore the importance of continued research and development in AR applications, paving the way for innovative teaching strategies that cater to the diverse needs of modern learners.