Suspension/Wheels/Tires/Brakes

HELP!!! Question about wheel/tire dimensions!

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Old Aug 25, 2006 | 06:27 PM
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Stephen C's Avatar
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HELP!!! Question about wheel/tire dimensions!

What size wheels will fit my tires? (tire dimensions= front: 235/45ZR17, rear: 255/40ZR17)

My current wheels are 17" x 8.5"; are those the only dimensions compatible with these tires? (Will 17" x 9" be too wide for the front tires? Will 17" x 8" be too thin for the rear tires?)
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Old Aug 25, 2006 | 06:47 PM
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Anybody? I need to find new wheels quick!
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Old Aug 25, 2006 | 07:49 PM
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rotard
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i would say 17x8 for the front and 17x9 for the rears
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Old Aug 25, 2006 | 08:18 PM
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Rotary Freak
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I would do 17x9/17x10. or 17x8.5/17x9.5

and 17x8 will be too small for the rears, but would work for the fronts.
and no, 17x9 is not too big for the fronts. manufacturer reccomended wheel width for 235/45R17's is 7.5 to 9".
also, recommended wheel width for 255/40R17 is 8.5-10.

so... if you want to get the same size wheels all around, you should be looking at 17x8.5 or 17x9.
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Old Aug 25, 2006 | 08:21 PM
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Thank you very much! You guys rock!!!!!!
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Old Aug 25, 2006 | 08:53 PM
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Not the first mention of offset and it will be different with the different widths.
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Old Aug 25, 2006 | 09:56 PM
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This is gonna sound really stupid, but what exactly is offset? What offset would you recommend given my tire dimensions above?
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Old Aug 26, 2006 | 11:00 AM
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CantGoStraight's Avatar
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Off set is what determines where the tire will sit in the sweel opening. Negative offset and more of the tire is inward of wheel opening (less lip on the rim) positive offset and the tire is more to the outside of the wheel opening (deep dish style lip) when you change width's you have to adjust the offset to keep the wheel centered in the wheel opening to insure it won hit suspension components or the fender lip. If you get it wrong then something gets damaged or won't work at all.
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Old Aug 26, 2006 | 05:42 PM
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Wink

Originally Posted by CantGoStraight
...Negative offset and more of the tire is inward of wheel opening (less lip on the rim) positive offset and the tire is more to the outside of the wheel opening (deep dish style lip) when you change width's you have to adjust the offset to keep the wheel centered...
Thats backwards CantGoStraight;

Negative offset gives a deep dish look, while positive offset will give the flat face design.

Examples, my Conquest comes stock with 16x8 -10 in the rear, and there is a nice deep lip..

New Evo's and STi's come with horrible AWD offsets, +35 thats why they are all lipless..

The more positive you go, the further in your rim will sit next to your suspension.

The more negative you go it pushes the outter lip of the rim out, and gives the "flush" look..

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Old Aug 26, 2006 | 09:19 PM
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Yup listen to mr TSI. hehe.

Basically think of it like this.

This it totally lamen so don't rag on me. i'm mr offset. hehe. Just trying to use dumb *** examples without making a drawing.

If your wheel is 8" wide with a +0 offset consider the "mating" part of the wheel to be directly in the center. Offset origin is always based on the center of the wheel.

Then a POSITIVE OFFSET indicates the AMOUNT OF MATERIAL THAT IS EITHER REMOVED OR DISPLACED FROM THAT MATING POINT. i.e. +50mm offset means they take about 2" off of that. So with +0 you have approx 4" front spacing and 4" backspacing. Well now with the +50 you will have 2" front spacing and 6" backspacing.

The more positive the offset the more INWARD the wheel will sit, the lower the offset the more OUTWARD towards the fender it will sit.

i've always wanted a conquest cause i have a few extra wheels from my widebody FC's that I am sure would fit. My neighbor has a sweet "laser Blue" color one. Oh i always wanted that. BLack leather too.

HAHA, you said lipless when we consider the EVO to give one of the larger lips for a Transversely mounted engine car. hehehehehe.

You're totally in the old school celica supra, corolla, SA22 4x110 era. lolz. Too bad it's not like that anymore, minus the Z33.

Thanks, Rishie
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Old Aug 26, 2006 | 09:26 PM
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So basically here's your offset ranges on the FD for stock fenders.

Front: 17x8.5 +40 MAX. Might still pull on your fender liner if lowered.

Rear: 17x8.5 +30ish to a 17x10 +45. Any width or offset in between those should be fine.

REMEMBER THE WIDER THE WHEEL, THE HIGHER THE OFFSET NEEDS TO BE. WHEN A WHEEL GOES WIDER BY SAY AN INCH, HALF OF THAT IS ON ONE SIDE OF THE "ORIGIN" AND HALF ON THE OTHER SIDE. YOU NEED TO ADJUST FOR THE HALF THAT IS ON THE "FENDER SIDE" BY INCREASING OFFSET.

i.e.
8.5" +40 has a front spacing of say:
8.5"/2 = 4.25 = +0 FS
Now with +40 that's basically 40/25.4mm/in = 1.57"
4.25" - 1.57" = 2.67" FRONT SPACING

Now for a 9.5" +40 since you're going an inch wider BUT OFFSET IS SAME, half inch on outside and half inch on inside, the wheel will stick out by about 12mm more towards the fender. You adjust this by making the offset 12mm higher to push it back in.

So 9.5" +52 Front spacing is equal to a 8.5" +40 front spacing.

Hope that helps also.

My numbers are not nearly exact and front spacing + backspacing will always = WIDER than the WHEEL's printed width. A 8.5" wide wheel is actually 9.5" to 10.0" wide front outside of rim edge to outside of rim edge.

Peace, Rishie
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Old Aug 27, 2006 | 01:22 AM
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Look at the spec sheet for the particular tires you will be using. The spec sheet will have a "recommended rim width" range. The range can vary slightly from one specific tire model to the next, so look at the one for YOUR SPECIFIC TIRES.

Tire Rack has spec sheets for many tires. Click the "Specs" link in the tire listing on the search results. Here is an example:
http://www.tirerack.com/tires/Spec.j...omCompare1=yes

-Max
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Old Aug 27, 2006 | 06:06 AM
  #13  
CantGoStraight's Avatar
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Originally Posted by Sideways Star
Thats backwards CantGoStraight;

Negative offset gives a deep dish look, while positive offset will give the flat face design.

Examples, my Conquest comes stock with 16x8 -10 in the rear, and there is a nice deep lip..

New Evo's and STi's come with horrible AWD offsets, +35 thats why they are all lipless..

The more positive you go, the further in your rim will sit next to your suspension.

The more negative you go it pushes the outter lip of the rim out, and gives the "flush" look..

Damn should have proof read that post first, (not sure if I would have caught it but thanks for setting it straight) I hate to confuse anyone or give bad information. I was thinking positive when I started typing the information just didn't proof it before sending it. Thanks again and sorry for any confusion, but now you see why it's so important (offset) that is.
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