| Comment | The speedo on cars is a little off and will show you a few MPH more than you are actually doing. It Varies car to car. It can never under-read but the tolerance for over-reading your speed is 10% plus 6mph. So potentially your true speed could be 31 mph while your speedo shows 40.
I look at the GPS speedo on Waze, set the cruise when that reaches 40 and it is rare that anybody is overtaking me. I’m usually rolling by everybody or catching up with cars in front and having to slow off.
My own car is only a couple of MPH off but one of the company vehicles is showing 47 when GPS is showing 40. |
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