Methods and systems for improving the uniformity of a tire by determining one or more high speed uniformity parameters of the tire are provided. The high speed uniformity parameters can be determined by continuously acquiring uniformity data while ramping the tire to and from high speeds. For instance, measured uniformity data can be continuously collected for the tire as the tire is increased to high rotational speeds and decreased from high rotational speeds. The measured uniformity data can then be analyzed to determine one or more high speed uniformity parameters for the tire. For instance, the measured uniformity data can be corrected for non-high speed uniformity contributions to the uniformity measurements, such as contributions resulting from non-uniformity of a road wheel use to load the tire during uniformity testing, contributions resulting from mass unbalance of the tire, and contributions from low speed uniformity parameters of the tire.