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Old 01-18-2006, 01:44 PM   #1
eSToI Loco
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Default Will 1" increase throw off AWD/ABS/drivetrain systems?? going to a 225/45-18

For my winter tire, I ordered 225/45-18 tires which will increase the overall diameter by 1" (26" vs 25" stock). My rationale was to preserve the stock 4" sidewall (225/45-17) to protect the wheels especially during the pot-hole prone winter months since I am also getting a new set of wheels.

I am not concerned about increased rotational inertia since the tire/wheel is lighter than stock tire/wheel. Also, I know the speedometer will run slower, at 60mph I'll will be driving 62.4mph so this is not of a concern either.

My gut feeling is the 1" in dia will not cause issues with the ABS/AWD computer modules, but I have been told otherwise since these systems are calibrated to the stock 25" diameter. Aside for speedo off, will the 1" increase throw off these systems, other potential issues?

The tires have not been mounted yet so I still have time to send them back to the tirerack.

Please save your comments on I should have gotten a 17 tire for winter, blah, blah, blah.
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Old 01-18-2006, 04:28 PM   #2
waktasz
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You will be fine as long as you run 4 of the same size tires, which you are doing. Like 80% of the people here run some size that isn't quite the same as stock and have no problems
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Old 01-18-2006, 06:22 PM   #3
doubleurx
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I would be more concerned about clearance and the fact that now you can more easily pack snow in the wheel wells.
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Old 01-18-2006, 09:01 PM   #4
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speedo will be off. and yeah, I'd be concerned about clearance. Your tires are going to chew up the inside of your fender well every time you hit a bump.
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Old 01-18-2006, 09:07 PM   #5
eSToI Loco
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Quote:
Originally Posted by HomerJay
speedo will be off. and yeah, I'd be concerned about clearance. Your tires are going to chew up the inside of your fender well every time you hit a bump.
Not sure about that, the radius increase is only 0.5" (12.8 mm) if that was the case, people with lowering springs would be rubbing big time considering most drops are > = 20mm
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Old 01-18-2006, 09:09 PM   #6
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Quote:
Originally Posted by HomerJay
speedo will be off. and yeah, I'd be concerned about clearance. Your tires are going to chew up the inside of your fender well every time you hit a bump.
It is more likely that the fender well will chew up the tires.
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Old 01-18-2006, 09:10 PM   #7
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Quote:
Originally Posted by doubleurx
.... and the fact that now you can more easily pack snow in the wheel wells.
How is that?
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Old 01-18-2006, 09:37 PM   #8
doubleurx
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Quote:
Originally Posted by MannyMohawk#5
How is that?
I live in a high snow (400-500 inches per year) and have three cars. One an SUV, the other two are performace cars with lowered suspensions. When you have mimal clearance between the tire and the fenderwell, the frozen snow that builds up in the fenderwell becomes ice due to the friction of the tire constantly rubbing against it. On the SUV, due to the larger clearance this does not happen and the snow drops out of the well. On the lowered car, the snow turns to a solid chunck of ice that sticks to the well. Increasing the tire diameter will only make this worse.
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Old 01-18-2006, 10:03 PM   #9
MannyMohawk#5
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Interesting. We get a lot of snow where I live but I have yet to have this problem. Hopefully I won't.
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Old 01-18-2006, 10:45 PM   #10
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Your odometer will be incorrect as well, and will get more and more "off" the more you drive.
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Old 01-19-2006, 12:37 AM   #11
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I'm running 1" under, and the shop wouldn't let me install them unless I signed a document that said they would have no liability if any problems occured(Sears). I found it funny. They mentioned something about some Hondas have some issues with their ABS. Sucks to be a Honda I guess.

The speedo's off, but other than that, the tire diameter has no effect on ABS. Your end gearing/torque will vary accordingly as well.
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Old 01-19-2006, 12:46 AM   #12
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Quote:
Originally Posted by garface
Your odometer will be incorrect as well, and will get more and more "off" the more you drive.
but in a good way, since you will be covering more miles than indicated.

The stock speedo reads high by about 5% anyway. That big of a tire would almost compensate for it, making it closer to being correct.

no comment on whether it is a good idea or not.
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Old 01-19-2006, 07:46 PM   #13
eSToI Loco
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Quote:
Originally Posted by austinpike
but in a good way, since you will be covering more miles than indicated.

The stock speedo reads high by about 5% anyway. That big of a tire would almost compensate for it, making it closer to being correct.

no comment on whether it is a good idea or not.
Yes I thought of that also, OEM speedo is about 5% off, which will compensate with the larger wheel.
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