Gotta be one of my Pete peeves. Our '04 tahoe will sometimes slam 2 gears down. Can this truck hold top gear and if it drops down, 1 is it smooth? I'm particularly interested in being able to keep cruise control on our trips from charleston sc to Hendersonville ,nc. On i26. At least until we get to the big climb up the mountain as you enter NC. ** title should read "small hills".