The only mechs that will reliably break 100kph are lights and mechs designed to hunt lights and cap on conquest. These builds are virtually always limited to XL engines and missiles backed by medium lasers. "Strikers" like the cent and hunchback can expect to break 90 kph with a decent missile and energy based loadout but any ballistic centric build will struggle past 80kph, which is more than enough really as long as you play to support your team and its heavy and assault mechs.
Edit: On the Centurion and Trebuchet.
*The Centurion is really limited because the only thing it does well right now is what you see with the trialmech which is preforming as a durable SRM boat.
*The Trebuchet is basically just a crappy 50t Kintaro with JumpJets. It has way too few missile hardpoints to work well with streaks and it is not heavy enough to boat LRM's effectively. JumpJets are not enough to make it decisively better in any role.
Edited by MisterPlanetarian, 13 October 2013 - 10:44 AM.