Deep sump pans are nothing but good for automatic transmissions. A deep cast-aluminum sump, shown here with a filter-extension feature (mandatory for fluid pick-up), cools fluid better and gives the C4 greater capacity. If racing, a deep pan and a cooler are vital, and for heavy-duty street use, you can't lose because cooler fluid temperatures enhance transmission service life. Average temperature is around 250-300 degrees. When temperatures become higher than this, transmission life shortens quickly.