Digital Product Passports (DPP) are a promising technology to enhance transparency around a product's sustainability, providing consumers with deeper insights into its environmental impact, material composition, recyclability, or ethical practices. However, it is unclear if and which of these detailed information consumers value. This paper presents an empirical analysis of consumer preferences for information transparency in DPPs, based on a survey of 230 German consumers. Applying conjoint analysis, we quantified preferences for various information attributes and levels. Unlike prior studies, our results indicate that consumers generally prefer detailed over basic information, with the highest utility derived from data on circularity, materials, and production. However, consumers with low environmental responsibility do not consistently favour more information. This study enhances our understanding of consumer preferences concerning the disclosure of sustainability-related product information. Practically, these findings guide policymakers, software developers, and organizations in designing effective and consumer-centric sustainability transparency within DPPs.