I also grew up around grey hounds, and the most amazing "race" I ever witnessed was when a coyote out ran 3 sets of grey hounds before eluding us, and there was no time for the coyote to stop and take a nap, it was one set after another and all three turn looses were good. Total distance run for the coyote was about 3 miles, and although the last pack of dogs almost caught him, almost doesn't count. From what I've seen in the past is if grey hounds don't catch the coyote with-in about the first 1/2 mile, they ain't gonna catch him. No doubt the coyote has way more stamina then a grey hound.
And like Will stated, not all coyotes are that fast, but every now and then you'll find one that is especially fast.
