70% X 165mm = 115.5mm (recommended)
70% X 175mm = 122.5mm (installed)
That means that the tire radius increases from (190.5mm* + 115.5mm =) 306mm recommended to 190.5mm + 122.5 mm) = 313mm.
*Note: 190.5mm is half your 13" rim diameter in millimeters.
Your tire will roll 1.02 times further for the same speedometer reading. If you are reading 50 miles per hour, your actual speed would be 50 mph X 1.02 = 51.1 mph.
You might not want to push speed limits as much as you might be used to.