Have you tried Sumo citrus??
a very sweet jumbo sized citrus hybrid. have been buying and enjoying tho the season for them seems over. not cheap-- one can cost 3 bucks.
did a little research online. the largest seedless mandarin grown in the USA. part mandarin orange. part satsuma. part navel. can weigh anywhere from half a pound to a pound with an average weight of 10 ounces. just available feb and march. this year was the first year this citrus variety has been available i believe. easy to peel. dont be put off by the banged up looking skin. technically called a Dekopon. Sumo refers to the size and to a nipple like knot on top of the fruit.