The invention relates to a new PET preform design that enables a more precise distribution of material in the bottle bottom and avoids the waste of material around the injection point. The thickness BWT.sub.min of the wall at the center of the gate or tip (3) (injection point) is reduced to a minimum in order to avoid the waste of material around the injection point when the preform is blown. This is particular important for carbonated soft drink application since the reduced amount of amorphous material at the center of the gate (3) helps to reduce the risk of stress cracking on the bottle base. Furthermore a step (4) having thickness WT.sub.max in the body wall thickness, in the region of the periphery of the base with WT.sub.max>WT, allows enough material to be available for the proper blowing of the bottle bottom making the bottle more stable.