Using the parking brake is a good idea. My friend's suburban has 110k miles on it, and his family parks it on a very steep driveway. Before 80k miles, they would never use the parking brake, and they had to put in a new tranny 3 times. After 80k, they have been religiously using the brake, and the tranny is running strong. Using the brake takes unnecessary strain off of the tranny, and, its the only thing they bother to teach you in driver's ed....