So far good for the Greaves Motorsport with regard to tyre choice. The choice to be the only LMP2 team with Dunlop's seem to be paying off.
Dunlop pulled out of all American Motorsport, so that's why no other car is using them and instead using Michelin. Greaves have a contract with Dunlop over in Europe so that gives them access to use Dunlops in Sebring, too.