Dr. Pepper has been on the shelves since the mid 1880's. It is a carbonated soft drink, with a cola appearance. For over a century, folks have enjoyed the unique blend of 23 flavors, never being able to put their finger on what exactly it is that makes it so good. A 20 fl oz plastic bottle of Diet Dr. Pepper contains 0 calories and 68 mg of caffeine. It truly is the beverage for any occasion, as any Dr. Pepper fan will tell you. Anytime you're at CAL Ranch, be sure to grab an affordable, delicious Diet Dr. Pepper.