Right. We have a 2011 GMC that had 31's on new and now has 33". At 70 it shows 66. I didn't know this when I bought it and was surprised I was passing everyone on the freeway. Legal limit is 80 so I was going ~85. My wife was driving our Camaro following me home and had to get close to 100 (She enjoys the Camaro) to catch me since I left a bit before her and let me know what my speed was. Good thing I didn't catch the attention of the HP. Her too.
