New restrictions on gasoline components mean that oxygenates and aromatics must be replaced by other high octane components. The dimerization of linear butene to form high octane gasoline blending components is evaluated under liquid phase reaction conditions over a number of different heterogeneous catalyst systems. These fall mainly into the category of solid acid catalysts as well as metal oxide on support catalysts - with supplementary examination of fluorotantasil and ion exchange systems. The parameters determining performance are the conversion of feed and the blending octane number of the raw product as well as the stability of the catalyst for sustaining these product properties. Subsequent deactivation of the catalysts is measured by the decrease in both these parameters. An amorphous silica alumina catalyst is found to give optimal performance according to these criteria.