Board Thread:Questions and Answers/@comment-33062853-20171016141954/@comment-26066818-20180223185605

In Son of M, Quicksilver had lost his speed powers and was given a completely separate power set by exposure to Terrigen, allowing him to time jump forward in time. He had no speed powers during this, and merely vibrated at a unique frequency to move through time. So, in comparison to the Flash, Quicksilver has never been fast enough to breach the time barrier by running. His time travel ability was accomplished through non-speed means.