205 or 215 or 225?

[brocklanders]

I tried to search for more info on this, but nothing came up?
Anyways I'm replacing the stock 205-50-17's and have seen different deals with varying sizes. I'm going to keep the 50 series, but 215's or even 225's would be interesting. This will be on a completely stock M3 sport GT, will there be any rubbing issues? I think 225 may be pushing it, but I thought I'd ask :)

[Noisy Crow]

You are going at this backwards.

1. What size rim will you be running?
2. What width tire do you want?

Those two, along with the overall tire diameter (which needs to stay close to stock) will tell you whether you need 40,45,50, or whatever series.

And if you search a bit you find lots of people running 225 width successfully. The key is to use a rim with the correct offset.

I'm running 225/45R17 on 45 offset rims, dropped on Prokits, no rubbing.

[brocklanders]

Stock 17" GT wheels. 205 or 215 I really don't care, but for some reason 215's seem to be a bit cheaper in most brands I've checked. i just want to make sure on a dead stock Mazda 3 sport GT this won't be an issue.
Thanks.

[Gizzmo_jr]

205/50 or 215/45 on the stock rims. They are only 6.5 wide so anything wider is a no no IMO.

[condor888000]

Agreed.

[thanu31]

would a 235 work on a mazda3 gt?

(on a 8" rim)

[condor888000]

Depends on drop, alignment specs, and wheel specs.

[brocklanders]

why the 215/45 as opposed to 215/50?

Thanks for the responses!

[Gizzmo_jr]

50 would make the outside diameter of the wheel bigger, 45 is just slightly smaller.

[brocklanders]

Sorry, REALLY showing my ignorance here, but it's already 50 series stock, wouldn't making it 215 just make it wider?

[S.F.W.]

Sorry, REALLY showing my ignorance here, but it's already 50 series stock, wouldn't making it 215 just make it wider?

http://www.torontomazda3.ca/forum/showthread.php?16846-A-Z-of-TIRE-INFORMATION

[condor888000]

And the ~1.5% undersize by going to 215/45 is well within the acceptable figure (~3% variance).

[joe_rocket65]

Sorry, REALLY showing my ignorance here, but it's already 50 series stock, wouldn't making it 215 just make it wider?

The 50 referrs to the height of the sidewall which is a percentage of the width. 205/50R17 means the sidewall is 50 percent of the width. If you go with wider tires, ie 215 or 225 you would need to go with a lower number series in order to keep it close to stock circumference otherwise your speedo will be off. 215/45R17 have slightly smaller circumference than OEM and 225/45R17 slightly larger. There are a number of tire size calculators out there that you can use to figure out how much of a change from OEM your new tires will be.


50 would make the outside diameter of the wheel bigger, 45 is just slightly smaller.


Just so there is no confusion a 50 series would make the outside circumference of the wheel bigger or the length of the diameter bigger.

[Gizzmo_jr]

length of diameter

[JaYson]

if you're looking to get rid of your EAGLE RS-A's one at a time, im in the market for a 205 50/R17 at the moment!

[m_bisson]

length of diameter

increasing the diameter also increases the circumference.