According to the Federal Trade Commission, a "Warranty of Merchantability" and a "Warranty of Fitness for a Particular Purpose" are both implied warranties (that is, unspoken, unwritten promises). A "Warranty of Merchantability" is a promise that the vehicle will do what it is supposed to do. This covers basic functions of a car, such as running. A breach of this warranty would exist if the dealer sold the vehicle and it did not work properly.
A "Warranty of Fitness for a Particular Purpose" would apply if the dealer sold you a vehicle promising that it would serve a certain purpose, such as hauling a trailer or a boat. The vehicle must be able to serve that purpose, or the deal may have broken this warranty.
We would like your feedback on this Personal Finance Frequently Asked Question.