This paper introduces a new method to screen crude oils for applicatibility of the air-injection/in-situ combustion process. Testing is performed at reservoir conditions, up to 41.4 MPa, with a specially modified accelerating-rate calorimeter (ARC(TM)). ARC results are shown for four medium-and high-gravity oils, combustion-tube data is presented, and air-injection field data are discussed and compared. We interpret that the continuity of the ARC trace ties in kinetics, combustion-tube, and field air-injection results. Thus, a method is available to delimit the envelope of applicability of air-injection/in-situ combustion to those oil reservoirs where the probability of technical and economic success is greatest.