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 created 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 down wind and, in the other, it propagated upwind. In both tests, drop-down from the body panels onto the tires, which then resulted in ignition of the tires, was an important feature of the mechanism of fire spread. Once the tire began to burn, the rate of fire spread increased followed by rapid spread throughout the remainder of the vehicle until it self-extinguished. 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.