Here are some photos from today. I looked up pomelo and they have winged petiole but this one doesn't.

The photo of the leaves on this page look similar?
http://www.citrusvariety.ucr.edu/citrus/yuma_ponderosa.html

Photo of the fruits.

Could be Ponderosa lemon; the leaf does not look like pomelo

Fruit looks like Cuban shaddock to me. But I don't own one. Just going off pictures.

Yuma ponderosa and Cuban Shaddock are considered by many experts to be the same variety. It does look like a Cuban Shaddock, which is a cross between a Pomelo and a Lemon.

If it's healthy I'd just leave it. The C.S. is a very tough tree, and I personally like the fruit.

I have one. It tastes like a mild lemon. You can pick them when they are fully yellow. It does have a lot of seeds, but there is so much juice from one it doesn't matter too much. I usually juice them, they make a really nice lemonade.

It does look like Yuma ponderosa/Cuban shaddock. UC Riverside's Citrus Variety Collection page:
http://www.citrusvariety.ucr.edu/citrus/cuban_shaddock.html

It says "Season of ripeness at Riverside: October to November." Really? We have to wait for 6 months to ripen? When we moved in in mid-March, the fruits were already that big but much greener. They are finally getting yellow.

Sometimes trees fruit off season. Just pick them when they're fully yellow and when they're a little softer than rock hard.