I use castrol high mileage 10w-30. I would not use the 5w-30 that honda says to use, they also say change the oil every 7,000 to 7,500 i think it was, I read that on top of the air filter compartment!

Reason be, its an old engine 17,000 more miles than yours, synthetic for a engine that old is not good, unless your were to get a tuneup, with new seal and gaskets, and all the other bla bla bla!