Taller Tires & Cruise Control

[MidwayJ]

Are you able to edit wheel diameter in FORScan to eradicate the issue?

How does Ford configure it between non-PP, PP and DH HP?

My understanding is Forscan can be used to adjust speedometer calibration error, but I haven't seen anyone report using it for the cruise control issue.

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[Andy Feuer]

That is my exact setup and I don't have any issues using my Cruise Control, not that I use it much.

Awesome, thanks Aggie! I'm know someone said they had 285/35 and 305/35 and they had issues.
I would post the thread, but it was a thread about "here's my new wheels" (or whatever), and it spun off into this cruise discussion.

 

[MidwayJ]

From what I got from the other thread, that can't fix it. Evidentially there could be 1 of 2 problems, or both.
1. The regular cruise wont work due to the RPMs being different from stock.
2. The adaptive wont work because the camera height is taller (higher).

So if anyone with 20's can try their regular cruise, and adaptive cruise we will know. It would also help to state your tire size.

If the issue is due to camera height, I wonder if lowering springs can potentially offset the height increase from taller tires.

 

[MidwayJ]

Dealer told me that if you have the adaptive cruise option, still can’t just switch to standard cruise in settings because that is dependent on camera input also. Not sure if problem exists in cars that have only Standard Cruise.

This is a good question and might explain why some with the same size tires have the issue and some do not.

 

[MidwayJ]

That is my exact setup and I don't have any issues using my Cruise Control, not that I use it much.

Does your car have adaptive cruise control?

 

[Aggie1999]

Does your car have adaptive cruise control?

I honestly don't know. I don't think so. If it does I've never used it.

 

[MidwayJ]

Awesome, thanks Aggie! I'm know someone said they had 285/35 and 305/35 and they had issues.
I would post the thread, but it was a thread about "here's my new wheels" (or whatever), and it spun off into this cruise discussion.

Pretty sure it was @ChitownStang that said he had issues with 285/35 and I think 315/35.

 

[ChitownStang]

Pretty sure it was @ChitownStang that said he had issues with 285/35 and I think 315/35.

Yep, verified the new wheels broke my shit!

 

[Andy Feuer]

Yep, verified the new wheels broke my shit!

Can you elaborate please?

 

[MidwayJ]

Went back stock (305/30/19 26.6” Front, 315/30/19 26.5”Rear). Problem solved. Went back to 20s with 285/30/20 (26.8) front & same 305/35/20 (28.4”) Rear. Problem back.

Wow, I understand why you're frustrated. Based on what the dealer said initially, you would think the problem was the front tires. The new front diameter of 26.8" should be close enough.

 

[robvas]

Could it be the rake (taller rear than front tilting the camera down) causing the camera not to work properly? Makes zero sense than an inch change in height would affect it.

 

[goodlettjr]

Since there is some mention that there hasn't been any feedback, I figured I’d share some real world feedback for anyone considering a taller tire setup on a GT PP car with adaptive cruise.

I’ve got a '24 GT PP with adaptive cruise, and a little over two years ago I moved away from the stock PP wheel/tire setup. I’m currently running:

• Rear: 315/35R20
• Front: 275/35R20

I did not change anything in Forscan or adjust tire size settings in any module. Just bolted them on and been rolling ever since.

For context, I use adaptive cruise all the time. Both on highway trips and daily driving. In 2+ years and about 38K miles, I’ve had zero issues. No warning lights, no weird cruise behavior, no ABS complaints, nothing noticeable in drivability.

I was actually planning to go in and update the tire size with Forscan this afternoon just to make everything technically “correct.” My Windows laptop is currently out of commission, so I needed to load Windows onto my MacBook Pro first before diving in. Life got busy… and honestly, since everything has been working flawlessly, it hasn’t felt urgent.

 

[goodlettjr]

Could it be the rake (taller rear than front tilting the camera down) causing the camera not to work properly? Makes zero sense than an inch change in height would affect it.

I agree with that theory. In my mind, If it was just ride height then everyone that lowers their vehicle would be experiencing issues.

 

[ChitownStang]

Can you elaborate please?

I installed 285/35r20 and 315/35R20 and lost all cruise control abilities

 

[robvas]

I agree with that theory. In my mind, If it was just ride height then everyone that lowers their vehicle would be experiencing issues.

You're just barely an inch taller and the other guy is over 1-1/2" inch. Maybe that's enough?

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