Certain CBers keep bringing up how bad Utah's offense is, but to your point, Utah's largest loss was only by 13 points, despite how bad their offense is. Three of their four losses were by a single score.
Utah's defense will limit BYU's scoring. The key is whether or not Utah's defense will get turnovers. If they don't, BYU will grind out a win. If they do, the outcome of this game becomes very much in jeopardy.