Two full-scale burn tests involving identical side-by-side all-terrain vehicles were conducted to evaluate fire spread, changes in temperature distributions over time, and how burn patterns correlated to the known point of origin of the fires. The fires were initiated by igniting body panels at opposite corners of the vehicles such that in one test the fire propagated downwind and, in the other, it propagated upwind. In both tests, drop-down from the body panels onto the tires resulted in ignition of the tires. This was an important feature of the mechanism of fire spread. Once the tires began to burn, a transition occurred and the rate of fire spread to the remaining portion of the vehicle increased. Although the time between fire initiation and this transition was significantly different in the two tests, the time to spread and to consume the remaining combustibles within each vehicle was relatively consistent, independent of wind direction. The variation of damage to painted surfaces, oxidation patterns on steel surfaces, and melt damage to aluminum components after the fire were similar in both vehicles but were not useful in determining the area of origin of the fire.