This paper addresses the development of a practical method to predict fuel stability, which is faster and as reliable as existing methods. The new test applies a technique known as Pressure Differential Scanning Calorimetry (Pressure-DSC) and appears advantageous in several respects. 1. It relates reaction enthalpy, in a novel approach, to fuel stability. 2. The test can be completed within 24 hours. 3. Small amounts of fuel suffice for a complete test (≦100 mg). 4. It should be possible to develop a highly automated, micro-processor controlled tester.