Snow tires effect on speedometer?

[Mrmike]

Just got my '23 OBX. It came with 225/60 R 18 tires. My snow tires are 235/60 R 18. Will the speedometer compensate for the height difference. If not how far off will it be?

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[rdc17]

It will be off by a tiny bit unless you reprogram the tire size with Forscan

 

[PaulOinMA]

There are online tire size calculators show you how much the speed is off: speedometer reads and actual speed. I have some bookmarked. You enter both tire sizes. Very easy.

 

[AndyMac204]

that tiny amount you should be fine. you are only going wider and not taller.

 

[Meanderthal]

that tiny amount you should be fine. you are only going wider and not taller.

When you go wider, you also go taller. In this case the sidewall height is 60% of the tread width. This user will be going slightly faster than the speedometer indicates, probably about 1% (without looking up the specifics on www.tiresize.com).

 

[Mrmike]

When you go wider, you also go taller. In this case the sidewall height is 60% of the tread width. This user will be going slightly faster than the speedometer indicates, probably about 1% (without looking up the specifics on www.tiresize.com).

Thank you for putting it in layman's terms.

 

[Mark S.]

Thank you for putting it in layman's terms.

Everything you ever wanted to know about sidewall markings in (mostly) layman's terms.

 

[RSH]

With the larger diameter of your snow tires, you will have speedometer error, though nothing drastic
Depending on speed the error varies.
Example the max difference at 90 MPH is 1.6 MPH, at 60 MPH its 1 MPH.
Who knows the accuracy of the speedometer anyway, I've compared it to GPS while on the highway, seems to track pretty well, but I have even larger tires than you. What I'm saying is that the error isn't enough to worry about.

 

[GoHack]

Just got my '23 OBX. It came with 225/60 R 18 tires. My snow tires are 235/60 R 18. Will the speedometer compensate for the height difference. If not how far off will it be?

I just upgraded my OEM Pirelli 225-65-17 to the 235/65/17 Falken Wildpeak A/T, and I see very little, if any change.

I've compared my speedometer to my GPS reading and they're pretty much dead nuts.

 

[RSH]

Just got my '23 OBX. It came with 225/60 R 18 tires. My snow tires are 235/60 R 18. Will the speedometer compensate for the height difference. If not how far off will it be?

You most likely wont even notice.

 

[Mark S.]

I just upgraded my OEM Pirelli 225-65-17 to the 235/65/17 Falken Wildpeak A/T, and I see very little, if any change.

You can do a comparison between two different tires sizes at tiresize.com. It will show the percentage difference and indicated vs actual speedo readings.

 

[GoHack]

Once again, I've compared my speedometer reading w/my GPS speed readings and they're pretty much dead nuts when it comes to speed.

The 235-65-75 is Ford's optional tire size, which is why I went w/it.

 

[Dperry285]

Just got my '23 OBX. It came with 225/60 R 18 tires. My snow tires are 235/60 R 18. Will the speedometer compensate for the height difference. If not how far off will it be?

No, go to dealer for recalibration

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