Not true since US people only make up a small part of Italy's tourism. Many people from all over the world flock to Italy.   Oddly, Italy and France (and good old Blighty) are known for being Europe's smallest tippers but saying that Europeans can and will tip either by rounding up to the next 10 pounds or Euros etc or adding around 10% give or take some.   As tours are a little different in tipping terms it is up to you. You could do what you normally do stateside or see what others do. We