15inch wheels?
 

I got a 2004 mazda3 2.3 liters 5door. Original wheels are 17 inch. can i put 15 inch wheels and 195/65/15 tires?? it's only for winter since 15 inches tires will be cheaper. i just don't know if i can put 15 inch wheels on it

Yes, without looking at the exact tire size for your 17" wheels, you likely can. The important thing is that the tire's outside diameter stays the same. Also, using tires that are narrower is better for winter driving. A good place to check to compare tire diameters and recommended sizes for all season and winter is Tirerack.com. Remember, too that the higher profile tires have another advantage--they handle pot holes better because there is more rubber to absorb the slam from a pot hole.

You can only go as low as 16 inch wheels with a 2.3 liter. The brakes are larger on the 2.3 liter Mazda3's.

like James said due to the 2.3L's brakes being larger the smallest wheel that will fit over the calipers/rotors is a 16". Even so a 16" winter tire will be cheaper than a 17" and will perform better with a larger sidewall and narrower tread.