Hello all... I have not seen this answered befo

I have a 1998 Jeep Wrangler Sahara with the (original factory Goodyear)
30" wheel option. The tires are now a bit worn down and I am looking
for new tires.

1. What is the biggest (and fattest) tire I can install on the same
wheels? I heard something about a 31" will fit. I don't want to do the
lifting bit... just want something cool looking!

2. What are the best tire manufacturers for the jeep?

3. If I have to replace the flares, no problem. Any downside to
upgrading the tire size like fuel economy, stability, etc.?

4. With bigger tires, do I need the speedometer & odometer adjusted?
Each turn of the wheel will cover a slightly longer distance, won't it?