I just bought a used 2006 4d AT. It came with p235 tires and I believe it's sports-tuned.

What does that mean?

Can I slap on some P215 tires or do I need to take it in to get re-calibrated or something?

 

why would you want to put smaller width tires on stock rims? that's just plain stupid.

 

I'm not going to. But I'm wondering if I want to switch to P215 tires, is that possible?

It's the sports tuned package so isn't the car calibrated differently compared to regular?

I'm just trying to learn all this...

 

you can if you wanted to.. any time you get new tires (even if it's the same brand and sizes), you should get the car aligned. I don't think anyone really gets the speedometer calibrated though.

 

But would I need to buy anything else besides the tires? Like another set of rims for the tires to fit on?

LOL my knowledge of cars is so rudimentary and I've never cared because I used to drive Corollas and Accords. Now I got a car I really like and want to take care of and know inside out.

 

if you're on stock 03-06 sedan rims (17" or 18"), the tires will fit fine on them.

 

But still, what's the difference between a standard and a sport-tuned package? Can you go back and forth?

 

Yes, dont worry too much about.

You also have stiffer suspension too. Just get any wheel and tires you want, shouldn't mess anything up as long as you are RWD. If you are AWD make sure the ending diameter is same for all 4 tires.

 

the factory tire size is 215/55/17 and the sport package comes with 235/45/18. Both tire sizes have near identical overall diameter. My winter wheels are 17" six spokes from an '03 sedan with 215/55/17 blizzaks my spedometer is spot on.

Sounds like you have the sport suspension which has 18" wheels, stiffer springs/shocks/struts and a VLSD rear differential.

 

^ Listen to this guy.