Vibrational electron energy loss spectra were measured for propane at incident energies of 3, 6, 10, 15, 20, and 25 eV at scattering angles of 40degrees, 55degrees, 70degrees, 85degrees, and 100degrees. The spectra are compared with the results of ab initio calculations using a recently developed two-channel discrete momentum representation method. Good agreement between theory and experiment was found for large scattering angles and energies above the resonant region. (C) 2004 American Institute of Physics.