I think I seen on here someone asking how to adjust the nav so it could calculate where you are a little better, but couldn't find anything in the search. I'm talking about when your coming up to a turn or a exit on the highway it's a bit delayed. Example I'll be turning off the highway and it will still show me on the highway for a couple of seconds. Is there some way to adjust it so it could read where you are a little better? I could be mistaken, but maybe it had something to do with the tire size or something like that.