Is alignment needed when swapping wheels out?

[mallaki]

I will be swapping my OEM (non-HP) five-spoke wheels (255/40 R19 fronts and 275/40 R19 rears) with HP wheels (305/30 R19 and 315/30 R19).
The HP wheels are already balanced with Michelin Pilot Sport4 S mounted…
I did a Google search, and some recommend it, while others say it's unnecessary, so I am more confused now than when I started.
The question is towards experts: Do I just swap them out, or do I /should I need to do an alignment?

Thanks. Stay safe and Happy Thanksgiving to everyone!
---Peter

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[LOL WUT]

It’s not required unless your tire wear seems incorrect and it’s not due to over or under inflation. Changing the wheels/tires has no impact on your alignment.

 

[cerbomark]

I understand your question as you are moving the wheels out a small amount. I also are in the camp of "alignment not necessary". some may say it changes the suspension set up by moving wheels. If you know your alignment is good then I wouldn't tworry about it. If you are unsure then maybe I d check it after the new wheels are on.

 

[Charlemagne]

You don't need alignment, but you should change the tire sizes with Forscan because the diameter difference is quite big (-3% in the front, -4.7% in the rear).

 

[mallaki]

You don't need alignment, but you should change the tire sizes with Forscan because the diameter difference is quite big (-3% in the front, -4.7% in the rear).

I was told that the diameter difference is so minor (similar to normal wear and tear, also resulting in the diameter getting smaller) that there is no need to do anything else, and the computer will simply adjust for it.

 

[MD18EcoStang]

You need an alignment when you need an alignment. Wheels have nothing to do with it.

 

[skinnyb]

I was told that the diameter difference is so minor (similar to normal wear and tear, also resulting in the diameter getting smaller) that there is no need to do anything else, and the computer will simply adjust for it.

Computer doesn't adust for size.. I adjusted mine, mine had non HP wheels from the factory, original owner swapped for HP wheels. When I got the car, the size was wrong and speedo was way off (like 5MPH), I adjusted and made it a LOT closer.

But I agree about alignment. Tire size and wheels have nothing to do with alignment.

 

[AZ_Ryan]

I dont agree with the consensus.

There will be a .8" difference in ride hight upfront with the HP wheels/tires because of the difference in diameter, which will surely change the camber. And the new tires are 2" wider, which will exacerbate any excessive toe. Not to mention the alignment specs are different between HP and non HP.

So yeah, I personally would at least get a front end alignment.

 

[Bluemustang]

No. But if your alignment has not been checked in a while I'd recommend it.

 

[NightmareMoon]

I dont agree with the consensus.

There will be a .8" difference in ride hight upfront with the HP wheels/tires because of the difference in diameter, which will surely change the camber. And the new tires are 2" wider, which will exacerbate any excessive toe. Not to mention the alignment specs are different between HP and non HP.

So yeah, I personally would at least get a front end alignment.

Iit may not be obvious, but lowering from simply smaller tires doesn’t change the suspension arm positions, so it doesnt affect camber like lowering by way of shorter springs.

if the toe is fine before it will be fine after, but yes wider tires are more prone to feel darty if the toe is out

if you think some sort of imbalanced pressure on the different contact patches is going to throw off the alignment, all I can say is the suspension pivot points are well constructed not to flex that way.

my general advice is to check the alignment once and a while and if you havent checked in in a year or more (or never), changing tires is a good excuse to refresh the alignment, but no swapping wheels doesnt require a realignment.

 

[mallaki]

I can confirm that after swapping non HP for HP wheels – my speedo is now off roughly 4-5 miles with respect to Waze via Apple CarPlay… I confirmed Waze shows speed correclty and that is in sync on my other two cars – so no issues with Waze as some have suggested in other posts.

Now, I read some people recommend going to dealer, some advise against it and some recommend to recalibrate with Forscan.

If I go with Forscan, can someone who actually did it confirm what values needs to be updated?

From watching a YouTube video, my understanding is that the below two values needs to be changed:

1. Tire Circumference, mm
2. Tire Size

From https://tiresize.com/comparison/ - I can get my old values and new values. Is it as simple as updating them via Forscan and save/Write?

And if so, which mm values do I use. For the Front ones I get 2090 mm and for the Rears I get 2108 mm

Thanks,
---Peter

 

[AZ_Ryan]

No confirmation needed. HP tires on a non-HP car will cause the speedo to read 4.5 slow everytime.

I had the dealer use Forscan to reset mine. The circumference of the HP rears is 2108. (there is no value input for the front, as the speed goes off the rear tires).

Now here's the rub. Ford factory settings already run about 2 MPH slow in all vehicles from the get go. So, when you enter the correct circumference of 2108, IT WILL MOST LIKELY STILL READ 1-2 MPH SLOW. Don't be surprised!

I changed to 295/35-19s on the back, and now my speedo is spot on. So if you're really anal, maybe you can calculate the circumference of that tire size and use it to get closer.

Also note that any dealer reflash, like the recalls for the fluid light and power steering, WILL reset your tire values back to factory. Ask me how I know.

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