Preheat oven to 275 degrees. In a very large bowl, combine cereals and pretzels. In another bowl, mix the other ingredients until sugar is dissolved. I suggest using a hand mixer because it takes up to 10 minutes for the sugar to dissolve into the oil and butter.
Pour the sauce over the cereal mixture and then use a spatula or your hands to mix everything together and coat the cereal.
Transfer everything to a roasting pan or jelly roll pans with edges. Bake, uncovered, 75 minutes or until cereal is crisp. Stir thoroughly every 15 minutes.
