wider tires need new speedo gear?
#1
12-06-2001, 11:58 AM
wider tires need new speedo gear?
DRIVE AXLE TIRE SIZE PART # COLOR TEETH
4X2 AUTO 3.55 P235/70R16 A/S C9OP-A PURPLE 21
4X2 AUTO 3.55 P255/70R16 A/S C8SP-B ORANGE 20
this was posted earlier... the only difference is that the second one has a wider tire (255 vs 235)... why would it need a different speedo gear? the tires are the same height...
-sal
4X2 AUTO 3.55 P235/70R16 A/S C9OP-A PURPLE 21
4X2 AUTO 3.55 P255/70R16 A/S C8SP-B ORANGE 20
this was posted earlier... the only difference is that the second one has a wider tire (255 vs 235)... why would it need a different speedo gear? the tires are the same height...
-sal
#2
12-06-2001, 12:52 PM
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The tires aren't the same height.
The 235 is roughly a 29" diameter tire.
The 255 is roughly a 30" diameter tire.
The 70 in each of the numbers is the aspect ratio - the distance from the rim to the outside of the tire in each case is 70% of the width. You increased the width and kept the aspect ratio the same, therefore the tire diameter went up.
The 235 is roughly a 29" diameter tire.
The 255 is roughly a 30" diameter tire.
The 70 in each of the numbers is the aspect ratio - the distance from the rim to the outside of the tire in each case is 70% of the width. You increased the width and kept the aspect ratio the same, therefore the tire diameter went up.