I need the experts for this one.

[mannyjfk]

As many of you know, I want to replace my tires tomorrow (weather permitting) and I am having a tough time looking for what I currently have. I bumped into this person that has a set on 215/45/17. Right now I have 235/45/17. The question is, switching to that new size will be too much for my B6? The wheels I am using are are listed here. Please let me know so I can buy or pass if not safe.



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[Vahan A]

i wouldnt take the chance with the 215 but thats just me

[Exanimas]

It will fit just fine. Might give you the tiniest bit of stretch and probably won't be as comfortable as a 235/45 due to having a slightly smaller sidewall.

[Kwarner]

As many of you know, I want to replace my tires tomorrow

mr popularrrr

[Shayneduboulay]

Don't do that because it will look weird and throw off your odometer!!

[doublezero30]

Don't do that because it will look weird and throw off your odometer!!

this is not true. if the sidewall was skinnier, it would be. but the sidewalls on both sets have the same profile (45).

if these are winter tires, get the 215s. a skinnier winter tire is better. if you plan on driving year round, man up and buy some 235's.

[mannyjfk]

DoubleZ,

Cash is not the problem but I can't find the same ones. I am going to have to settle for Pirelli's P6 235/45/17.

[Baldphairet29]

hey check out tyrestretch.com if your looking for some pictures. one of my vw guys put me on to this just for a reference. they should totally fit though. hope this helps

[1ScientisT]

45 is the aspect ratio, or percentage of the width of the tire. So the sidewalls will be smaller because 45% of 215 < 45% of 235. It will slightly alter speedometer readings and the odometer will no longer be accurate.

[Kwarner]

this is not true. if the sidewall was skinnier, it would be. but the sidewalls on both sets have the same profile (45).

if these are winter tires, get the 215s. a skinnier winter tire is better. if you plan on driving year round, man up and buy some 235's.

they arent the same, 45 is just the percentage of the width.

[walky_talky20]

Correct. The 215 tire will reduce the sidewall by almost 1/4" (between the rim and road) as compared the the 235. This will tend to give a harsher ride. Also, because the tire is somewhat 'stretched' (skinny tire, wide rim), the sidewall will be somewhat stiffened, magnifying the harsh ride effect.

Also, because you have reduced the diameter of the tire by almost 1/2" (1/4" on top *and* bottom sidewalls), you have reduced the circumference of the tire by more than 2 inches. Not huge, but enough to throw off your speedometer by almost 3%. So when your speedometer reads "60mph" you are only traveling at about 58mph.

Tools: miata.net's tire size calcuator

[doublezero30]

you guys dont get what i was saying. the "45" is the sidewall height. the difference between 215 and 235 is close to nothing compared to going from a 45 to a 35. rolling diameter will effect your speedo more that the width of the tire. i run 225's on an 8.5" wheel and see no ill effects on my speedo from when i run my stock winter setup

[mannyjfk]

mr popularrrr

I only say that because I have been asking 10 questions a day.

[mannyjfk]

Baldphairet29 you sent me the the site tyrestretch.com and I saw the pics and I got sick looking at those 215/45/17. No way I will make my car look like that. I rather donate it. Thank you all for the information.

[diagnosticator]

I'm running 215/50/17s on my Avant, no problems. I like the extra side wall for some more cushion against the crap streets around here..

[BASARAB]

I ran 215/45/17 from march till December. The ride quality is fine, but wheel gap looks huge