Tire calcs - Hope it helps
I like to use this site when looking into tire changing.
The site is
http://www.1010tires.com/TireSizeCalculator.asp
And the chart for this discussion is
Stock Tire - 265/75R16 >
Search Tires Tire 1 - 275/70R16 >
Search Tires Tire 2 - 285/75R16 >
Search Tires Tire 3 - 285/70R17 >
Section Width: 10.43 in 265 mm
Section Width: 10.82 in 275 mm
Section Width: 11.22 in 285 mm
Section Width: 11.22 in 285 mm
Rim Diameter: 16 in 406.4 mm
Rim Diameter: 16 in 406.4 mm
Rim Diameter: 16 in 406.4 mm
Rim Diameter: 17 in 431.8 mm
Rim Width Range: 7 - 8 in
Rim Width Range: 7 - 9 in
Rim Width Range: 7.5 - 9 in
Rim Width Range: 7.5 - 9 in
Overall Diameter: 31.64 in 803.65 mm
Overall Diameter: 31.15 in 791.21 mm
Overall Diameter: 32.83 in 833.88 mm
Overall Diameter: 32.70 in 830.58 mm
Sidewall Height: 7.82 in 198.62 mm
Sidewall Height: 7.57 in 192.27 mm
Sidewall Height: 8.41 in 213.61 mm
Sidewall Height: 7.85 in 199.39 mm
Radius: 15.82 in 401.82 mm
Radius: 15.57 in 395.47 mm
Radius: 16.41 in 416.81 mm
Radius: 16.35 in 415.29 mm
Circumference: 99.39 in 2524.5 mm
Circumference: 97.86 in 2485.6 mm
Circumference: 103.1 in 2618.7 mm
Circumference: 102.7 in 2608.5 mm
Revs per Mile: 657.3
Revs per Mile: 667.7
Revs per Mile: 633.5
Revs per Mile: 636.0
Actual Speed: 60 mph 100 km/h
Speedometer1: 60.9 mph 101. km/h
Speedometer1: 57.8 mph 96.3 km/h
Speedometer1: 58.0 mph 96.7 km/h
Speedometer Difference: -
Speedometer Difference: 1.582% too fast
Speedometer Difference: 3.756% too slow
Speedometer Difference: 3.349% too slow
Diameter Difference: -
Diameter Difference: 1.55%
Diameter Difference: 3.63%
Diameter Difference: 3.25%