U7145 Tire\Wheel size change

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MattC74
Posts: 12
Joined: Sun Feb 06, 2011 12:33 am

U7145 Tire\Wheel size change

Post by MattC74 »

Hi, I went from 235/55-17 to 235/50-18. So my question is do I need to change this in my tune? And what are the values I'm needing?
Thanks
Fun4me
Posts: 63
Joined: Fri Mar 01, 2013 9:02 pm

Re: U7145 Tire\Wheel size change

Post by Fun4me »

MattC74 wrote:Hi, I went from 235/55-17 to 235/50-18. So my question is do I need to change this in my tune? And what are the values I'm needing?
Thanks
I think thats the same overall diameter. Best thing to do is go to the tirerack website and look-up the specs for the tire, you'll see "revs per mile". Then reload your tune, choosing modify before you install it and enable gear/tire change and change the revs per mile. The same size tires will have a slightly differant revs depending on the make/model of the tire, so its best to look it up on tirerack. GL
MattC74
Posts: 12
Joined: Sun Feb 06, 2011 12:33 am

Re: U7145 Tire\Wheel size change

Post by MattC74 »

Fun4me wrote:
MattC74 wrote:Hi, I went from 235/55-17 to 235/50-18. So my question is do I need to change this in my tune? And what are the values I'm needing?
Thanks
I think thats the same overall diameter. Best thing to do is go to the tirerack website and look-up the specs for the tire, you'll see "revs per mile". Then reload your tune, choosing modify before you install it and enable gear/tire change and change the revs per mile. The same size tires will have a slightly differant revs depending on the make/model of the tire, so its best to look it up on tirerack. GL

Cool thanks for the info.
BrianTim28
Posts: 1
Joined: Mon Mar 09, 2020 9:36 am

Re: U7145 Tire\Wheel size change

Post by BrianTim28 »

In this tire size comparison guide tirewheelguide, you can find the best tires for your car.
gordenbro1
Posts: 2
Joined: Sat Feb 01, 2020 7:55 am

Re: U7145 Tire\Wheel size change

Post by gordenbro1 »

Gotta admit I feel a bit dumb having to ask this, but my Google-fu doesn't seem to turn up anything meaningful that actually answers the question I have.

People seem to love going to wider or larger wheels and running tire sizes different from stock. However, changing the tire size will, in almost all cases, change the rolling circumference. This will have an affect on the speedometer. Is there some easy/simple way to account for this that I just haven't become aware of over all these years? Or are people just accepting that their speedometer and odometer will end up being incorrect by changing size?Metal Folding Chairs Manufacturer
Last edited by gordenbro1 on Fri Mar 12, 2021 7:24 am, edited 1 time in total.
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mikel
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Location: DiabloSport World Headquarters
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Re: U7145 Tire\Wheel size change

Post by mikel »

No, our tuners allow you to enter the new tire size values and it corrects the speedometer for you.
Mike Litsch
Holley Technical Sales Manager
Diablo Tech support by phone:
561-908-0040x4
M-F 8:00 AM to 5:00 PM EST
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