Information search is a critical component of the purchase decision process for most consumer durables. This paper postulates a descriptive model of information search and tests the hypothesized relationships using survey data obtained from a probability sample of new automobile purchasers. The results support the hypothesis that there are at least two unique components of prior knowledge: specific product knowledge and general product-class knowledge. The former causes less external search, the latter causes more external search. Cost of search was found to be negatively related to external search, while external search was found to be positively related to cost savings. Satisfaction was found to be related to cost savings but not to external search.