The Kelley Blue Book lists values for four-wheel all-terrain vehicles under the motorcycle section of its website; in addition, the NADA Guide also lists four-wheelers under motorcycles. The two blue books are unaffiliated, and valuations for the same four-wheeler may not necessarily match.
The Kelley Blue Book lists values for four-wheelers according to trade-in or retail value. Four-wheelers are grouped with motorcycles and watercraft by Kelley because all of these are considered powersports vehicles. As of 2015, Kelley requires ZIP code information from visitors, as values for vehicles vary by location.
As of 2015, the NADA Guide lists a somewhat smaller range of four-wheeler brands than Kelley. Values in the NADA Guide tend to differ from those given in the Kelley Blue Book. NADA's values are based on the latest vehicle transactions and reflect actual sales at retail or otherwise, while Kelley uses transactions plus a proprietary editorial process.