So in Civil War, the Black Panther suit seems to give the suit holder some extra speed, because the guy was running as fast as Bucky and Captain America.
So does it give extra speed? If so, how does that work?
According to Marvel, in the comics it's not the suit
T'Challa's senses and physical attributes have been enhanced to superhuman levels by the heart-shaped herb.
The Heart-Shaped Herb is a plant that only grows in the nation of Wakanda. In legend it was said to have been a gift from the Panther God, the local deity they worshipped, but in reality the plant had been mutated by a giant meteorite of Vibranium crashing into the earth.
As chieftain, the Panther is entitled to eat a special Heart-Shaped Herb which, in addition to his mystical connection with the Wakandan Panther God, grants him superhumanly acute senses, enhanced strength, speed, agility, stamina, durability, healing and reflexes
More information @ marvel.wikia.com
Note: There is no information (that I can find) regarding the powers and/or abilities in the MCU version Earth-199999 of the Black Panther. Logically this will be covered in the Panther movie.