gearing change?

Just curious, but many of you have changed tire sizes, most going larger. Have any of you changed your gearing (ring and pinion)? I know your supposed to to maintain exact transgression shift points, speedo readings and such (transferred torque, speed, et. al.) but I haven't noticed any mention of such changes. What are the affects?

Most of my driving is on the street, however I do get into some fairly precarious situations in the pursuit of fish and game far away from the beaten path. I haven't upgraded tires yet... coming soon-- so I was curious as to the affects of going to like 31s.

Thanks in advance!

apologies for the duplication having trouble with the pc and several sites!

31s aren't a problem, since '02s are essentially shipping with them in the form of 265/65R17 rubber on the SE SCs using the exact same gearing. I doubt there is even a speedo pinion change anywhere in the matrix now that even the 4-cylinder base XEs have 265/70R15 tires (no more 235-series) which are 30" size.
Several owners report that their speedometer was dead-on w/ their GPS speed indication after switching to 31" tires.

Brent