205/50-17 vs 225/45-17

[mfm22]

Looking for new tires . Currently have stock tires =205/50-17 run flats

In manual [2005 330 xi] there is listing for both sizes . What are the pros & cons of these 2 dif sizes .

Will the wider tire fit on stock rim?

 

[Big Daddy]

Yes they should fit with no problems, in fact the 225/45-17 is a plus size option for your car. In fact all these sizes are listed as plus sizes for your car:
Plus Zero
215/45-17
215/50-17
225/45-17
235/45-17

 

[echothreezero]

225 45 17 is the correct size if you wish to go to a wider tyre. How wide are your wheels? If you are not sure, I would suggest that the wider tyre may look a little chunky on the rim, but the only way to find out is try it.

 

[mfm22]

Got the car last week with 17k miles . its 330 xi all stock .

I was wondering if changing to this size affects height ? which will affect speedometer . But 45% of 225 = 101.25

50% of 205= 102.5 not much difference or is it?

 

[Big Daddy]

None of the sizes listed will adversely effect your speedo.

 

[echothreezero]

They are around half a percentage point different in overall circumference/diameter. anything up to 5% is considered acceptable.