Hi, new forum member and new (used) mazda 5 owner so go easy . I recently got a 2010 Mazda 5, and am about to put a rack and pinion in it, but will also need tires soon. The stock tires are the 205/50/17...but I have an opportunity to get some 235/55/17, and was wondering if those would work without getting me into too much trouble. I understand the speedometer might get thrown off a little but I can deal with that. Should I expect a drastic change in handling or other problems with that type of change? Eyeballing it and doing a quick measure, it looks like they will physically fit in the wheel well, but not sure if the fronts would rub in turning. The stock size rides a little bumpy to me, so I was hoping to find some tires with a little more meat on the sidewall that would hopefully help that problem, and I do like how it handles, but I am willing to trade a little of that away, if it could make it a little smoother of a ride. I'd like to solve the tire question before I get it aligned, after I do the rack and pinion. Thanks for any help.

 

it appears that car came with 6.5 inch and 52.5 offset rims.
Thats a big difference especially on little 6.5 inch rims. 235 tires are too big for 6.5 inch rims and won't fit . the tires also might rub the fender. and it's almost 10% difference in diameter.
You may want to get some 7 inch or 7.5 inch rims with a lower offset rim and maybe not as wide a tire. Check aftermarket rims at tirerack or discounttire. Or maybe check to see if mazda 7 inch offset 45 rims might work. mazda CX5 have 7 inch 45 offset that may be possible. You need to test fit a rim before you install any tires or they may be non returnable.
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Go to tiresize.com and wheelsize.com to compare and see which rims and tire setup may work best.
​​​also be mindful and dont stray too far from the original diameter tire setup.

When switching rims and tires, it's best to stay as close as possible to the OEM sizes. F.i. 7 inch rims over 6.5 inch. 215 mm wide tires instead of 205, etc. Keep the diameter difference to 3% or less.

Also, that car also came with OEM 205 55r16 x 6.5 tires and rims. You could go to salvage yard and get some 16 inch rims cheap and maybe put 215 55r16 tires on. Again check you fitment on wheelsize.com. imo 215 55r16 on mazda 16x6.5 rims may be a good setup for you.

 

Welcome to the forum

 

Hi, the original stock size is 205/50/R17, according to the door jamb sticker. This is the 'sport' version, so that is probably why it has 17" from the factory. Also, it does have aftermarket rims on it, but I have no idea how to tell what size they are, other than diameter (17"). I'll have to figure out how to measure the offset, i'm not very familiar with how all the wheel and tire sizes work, other than diameter.

 

The wheel should have a brand name on the inside somewhere? Unless it is a Chinese knockoff of a popular brand?

 

Look for offset in the back of the rim...
for example the offset below is 45, diameter is 17 and width is 7.

17x7J ET 45
Or
7J x17 H2 ET 45

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It looks like they are "MKW" wheels. If the parts come tomorrow, I will be working on the rack and pinion, and will look for the numbers then, thanks.

 

Yes good to know now you can go to MKW website and get the correct information. I often see members posting the formals that they found on the internet but in the real world these same people have no clue how to measure a wheel correctly and then place the wheel on an axle and measure ALL the important point for clearance! And those are before the tire is included in the measuring !

 

Ok, so after a long day of working to get the rack and pinion out (still have to lower some subframe bolts to get clearance), I got some numbers. And some photos. Here are some numbers: ND-1 2250 17x7.5J, and M115 ET40. Does that help at all? I understand the 17x7.5 (I think) but the rest is foreign to me. I also have a couple photos (also with imgur link for better zooming): https://imgur.com/a/cJQoSD1

 

M115 is the models numbers so it's an MKW M115 rim. The offset is 40 on a 7.5 inch wide rim which pushed the rim/tire outward towards the fender by approx. 25 mm. Check and see if it rubbed anywhere. If not, then check your existing clearance and you may be able to put wider tires on this rim but watch your diameter and try to not go more than 3% larger. Remember wider tire will be into the fender more.
​​​​​some of your model year came with 16x6.5 with 52.5 offset. That would be a more ideal setup and allow you to put tires with more sidewall on. Or if you find a mazda rim with 16x7 inch with 45 offset that may allow you to also use slightly wider/larger tires as well and greater sidewall. If it's currently got 205, try to stay as close as possible to OEM and not to go wider than 215 preferably or 225 max.