TUFFY WALLED LAKE SUPPORTS OUR TROOPS!FREE OIL CHANGE FOR VETERANS & ACTIVE MILITARY! Tuffy Walled Lake proudly supports our troops. In appreciation for your service we are offering a Free Oil Change for Veterans and Active Military Personnel! Every Monday, Tuesday, and Wednesday from 7:30am - 8:00am. Please arrive by 7:20am. We take the first ten people per day. For your personal vehicle only. Must show military ID.