"Catalytic polyforming was applied to shale oil using isobutylene and n-butane as the added gasoline in an attempt to produce a more stable gasoline in higher yields from this source Houdry aluminum silicate catalyst in a fixed bed system was employed in all runs. The investigation was conducted at temperatures from 3600 C. to 5730 C. and liquid space velocities from 0.5 to 6. O. During an average run approximately 450 grams of feed (oil and gas) were passed over 1000 ml. of catalyst using a pressure of 900 lbs. sq.. in, I gauge. Isobutylene, but not n-butane, when used as the outside gas gave higher yields of gasoline at both high and low space velocities than could be obtained by conventional catalytic cracking of shale oil. Catalytic polyformir, gave maximum gasoline yields at higher space velocities and lower temperatures than catalytic cracking.. The gum content was essentially the same regardless of how the gasoline was prepared. The color instability of the shale oil gasoline was almost completely eliminated when prepared by catalytic polyforming."