PurposeIn marketing, most research on intention–behavior consistency (IBC) is dedicated to improving the predictive ability of stated intentions for future behaviors, with relatively less exploration into the precursors of IBC, especially those linked to regular durable goods void of ethical consumption characteristics. This study aims to focus on the antecedents of IBC for such products, specifically examining category-level and product-level IBC in light of consumer knowledge.Design/methodology/approachThe authors conducted a two-round survey to collect 3,560 Chinese consumers' vehicle purchase intentions and behaviors. The authors have also leveraged a large vehicle database (containing detailed vehicle attribute information) to measure consumer product knowledge (i.e. product judgment accuracy). A trivariate probit model was proposed to account for the potential selection bias arising from sample attrition while examining the effects of consumer knowledge on category- and product-level intention-behavior consistency.FindingsFindings reveal that 47% of the participants displayed category-level IBC, and within this group, a further 39% exhibited product-level IBC. Notably, product knowledge, manifested as accurate product judgment, correlates negatively with category-level IBC but positively with product-level IBC. Intriguingly, the negative association between inaccurate judgment and product-level IBC is less pronounced for consumers overestimating the target product than for those underestimating it. Furthermore, consumers with direct experience are less prone to show category-level IBC, but are more inclined to display product-level IBC.Practical implicationsVehicle marketers should prioritize consumers who show interest in their products but possess inaccurate knowledge, to retain whom companies can nurture their product knowledge. As for consumers with accurate knowledge, companies should try to expedite their purchase. Vehicle marketers also need to devise suitable advertising strategies to prevent consumers from undervaluing their products. For those overestimating competitors' products, companies can provide information to correct their overestimation and draw attention to possible confirmation biases. Vehicle marketers should encourage potential buyers who have shown interest in their product to participate in test-drive events, exhibitions, and other direct experience opportunities. Yet, for consumers still in the “whether-to-buy” decision-making phase, companies should not rush them into a test drive.Social implicationsIn the policy-making realm, governmental administrators can implement extensive consumer education programs, with a focus on the importance of product knowledge. This may involve providing consumers with accurate information and buying guides through various channels, which can help consumers make informed purchase decisions. Moreover, to foster healthy competition among vehicle companies, governmental administrators can establish regulations that require vehicle companies and other relevant industries to provide accurate and transparent product information, including performance, safety, and environmental aspects. Finally, in order to protect consumer rights, governmental administrators can also strengthen regulations to ensure fair treatment and safeguards for consumers throughout the purchasing process. This includes cracking down on false advertising and fraudulent practices, maintaining market order, and enhancing consumer confidence and purchase consistency.Originality/valueThis study is among the first attempts to examine the relationship between consumer knowledge and intention-behavior consistency, especially for regular durable products void of ethical consumption characteristics. Responding to the call of previous literature (e.g. Morwitz, 1997), the authors distinguish between and examine two forms of intention-behavior consistency simultaneously (using a sample selection model) and obtain more reliable conclusions. Moreover, the study's large-scale two-round survey had obtained individual-level purchase behavioral outcomes, which allowed the authors to measure each consumer's IBC at both category and product levels. More importantly, the authors show the opposite effects of consumer knowledge on the two forms of intention-behavior consistency.