How much data do I sync from the app to my account on average? Do I need a data plan?

We designed the sync to be data friendly The amount of data you transfer, really depends on your daily driving, usage of the map on the app, default sync mode. On average,  you should transfer around 50 MB per month, heavy users who drive daily transfer up to 150 MB per month. You can still sync data via your home or work wifi so you do not need a data plan at all.