The applicability of simulated distillation (SimDist) for the characterization of heavy oils and bitumen is examined with a focus on the fraction of the oil corresponding to the distillation residue. To assess SimDist, atmospheric equivalent boiling points from a SimDist assay, a conventional physical distillation assay, and a deep vacuum distillation assay were compared for three heavy oil samples from different geographical regions. All of the data were obtained from the literature. The SimDist data matched the distillation data to within its reported repeatability of +/- 7 degrees C in the range of 100-400 degrees C but deviated progressively from the distillation data beyond 400 degrees C, erroneously characterizing the oil as more paraffinic. The deviation in the SimDist boiling points is attributed to calibration curves based on alkane properties and possibly to the polarization of the liquid phase of the chromatograph by the aromatic and asphaltenic components of the bitumen. A Gaussian extrapolation of the SimDist data fitted to the boiling points below 400 degrees C matched the boiling points from the physical distillation to within +/- 10 degrees C.