KWayRacing

Another tech and I were debating this today. He was waiting on some tires to be delivered to our shop and I suggested he go ahead and do the alignment while he waited. He said no way that the new tires would alter the alignment. I called bull. I said that only thing that could possibly change would be ride height and only be a max of 1/4 in.(new tire 10/32 old tire 2/32 =difference of 8/32=1/4 and that small amount would not make any difference. And besides it was a stock honda he was aligning which only has toe adjustment and new tires would not change this setting. Any thoughts or definite answers?

TunerN00b

It doesn't really matter.

Though, if your alignment is currently off, any miles put on the new tires will be miles with unnecessary additional wear. For that reason alone, I'd go ahead and align with the old tires, or have them do the alignment at the same time as when they mount them, but not after.

And the car height change from old to new tires doesn't affect the suspension at all, neither does going to a different sized tire. Its only when you adjust the suspension to change ride height that the alignment changes.

KWayRacing

Exactly because spring determines ride height

Evs-One

If the tires are crappy enough it could throw off the reading of the alignment machine, not the settings themselves. He is right to wait for a new set of tires.

TunerN00b

Interesting. Good to know.

KWayRacing

How? The alignment heads are connected to the wheel which is bolted the the hub which is in direct connection to the suspension. So wgat I hear you say is that a perfectly aligned car can change tires and that would change the readings...thats wrong.

PatrickGSR94

iTrader: (1)

If the old tires are worn REALLY unevenly, then yeah, theoretically it could SLIGHTLY change the alignment readings after putting on new tires.

Tyson

after. why take any chances?

blaze the chemi

I had a great alignment on my car and put on a new suspension. I also rotated my tires from back to front on the same side. I got an alignment done and everything was in spec afterwards, but my car slightly pulled to the left because of severe camber wear that was on the rear tires just recently rotated to the front.

So yes I would wait until the new tires are on to get the alignment so the customer doesn't come back saying the tech doesn't know what he is doing.

Evs-One

You also have 5" of tire between the rim and the alignment rack.

Always do the alignment how the car will be driven...you or the same amount of weight in the drivers seat too!

KWayRacing

That doesn't matter. You could theoretically put the wheels on same height as tire wooden blocks and align the car. The tires don't change the position of the bolted parts. If they did when you got new tires you wouldn't need an alignment because the new tires would majically correct the alignement in the same way that it is suggested that worn tires will affect alignment.

Salami

Think about it for a moment. What are you doing when you do an alignment? You are taking measurements of a very small amount, correct? Precision counts. Measurements are taken so adjustments can be made to the suspension. The less accurate your measurements are the less accurate the adjustments to the suspension and the less accurate the alignment.

Not all tires are constructed exactly the same and will sit differently depending on air pressure, uneven wear patterns, etc. The only good reason to align a vehicle to old tires if they are staying on it. The only reason to align a vehicle to old tires when they are going to be replaced is "convenience", not because it is just as good.

PatrickGSR94

iTrader: (1)

This. Don't be lazy.

PGrizzy

I agree with this,but sometimes you don't have the luxury to put the new ones on first and it will only throw the machine off a litle,no enough to matter.

5SpeedEJ6

I would personally do it after I mount the new tires just to be sure the aligment is 100% accurate. I do not have any proof that it would be innacurate with the other tires, but I always felt like it would be different. That's just my .02 cents.

TunerN00b

You revived a 5 year old thread for this?

stupiduser

Who cares? There's good info in this thread and it ranks highly on google for relevant keywords.

grumblemarc

iTrader: (4)

Holy late for the party Batman!

Trevor Kroemer

So, I know this is way after the initial discussion, but like the previous late post, this comes high on Google search results. I wanted to make sure that anyone who finds this gets a full answer.

I have a 2010 Pontiac Vibe, for all intensive purposes, it is a Honda. I got new wheels, tires, and tps. I paid the extra to have it four wheel aligned.
They aligned it with my old 16" rims and tires and then balanced and mounted the new 17" rims.
The ride has felt fine (less then 100 miles of driving), but my friend, a certified alignment specialist, was upset when he heard they aligned it prior to installing the new wheels.
In my research I have found that replacing the tires has less impact on the actual alignment process, but if you are going from low profile to some mud rompers, or vice versa, the alignment will be slightly affected. If you are having new wheels put on, you should definitely make sure the alignment is done after instalation. Since it is a "wheel alignment" and factory specs are not perfect from one set to the next. The alignment adjusts the wheel to its proper position, and balancing ensures that the tires do not put extra fatigue on the staring components. If I missed something, please reply.
Thanks

ZachL

In this situation I would wait until after the new tires.

The wear to the new tires is so negligible, it's irrelevant to making the decision.

B serious

iTrader: (1)

It absolutely matters....especially if the old tires have an irregular wear pattern. Always tires before alignment.

Cot dang, boy. Errbody know dat.

Edit: why is a Pontiac Vibe "a honda for all intensive purposes"? ALL intensive purposes?

slowcivic2k

Since the behavior of the tires, new or used, cannot be compensated for on an alignment machine, and the fact that installed alignment equipment aligns to the rim itself, not the tire, means there is no real difference. I'm going to catch flak. Explanation:

The tires should be serviceable during an alignment, meaning they are not overly worn from left to right, that they are the same size, and that they are properly inflated. The vehicle must be evenly loaded as well, and ride height inspected. The alignment machine will take the tires as a constant. Any deviation will be interpreted as a mis-alignment. Example: Try aligning a vehicle with a compact spare tire installed. Since the machine expects a set of matching rims/tires, any alignment angle problem may be construed as a suspension problem to the machine. Most of us though, realize that a compact spare will affect ride height from side to side, and camber, at the least. (It is worth noting to me, that many tire facilities, including Firestone and Tires Plus will check your wheel alignment with a spare tire installed. I've seen it done..... and its great to watch!)

Slight changes in ride height are compensated for in the specifications for any given vehicle's alignment angles. If they weren't your alignment would be very unstable as the tires wear. These small changes in height are not enough to warrant adjustments out of range of factory adjustments. If you change rims and your spring ride height, you are altering a lot of suspension geometry, including bump steer, tie rod angle, scrub radius, and wheel returnability, etc.

In a typical exchange of tires, where the tires are evenly worn, and then replaced with new tires, there will be no noticeable difference in alignment readings, old or new. The only way for that to occur is by technician error (IE loose wheel, wrong tire, poor installation of alignment sensors, etc). Attempting to verify the alignment with a non-serviceable tire will potentially yield errant readings.

I should make an additional note, that new tires may grip the road with the current alignment angles differently, at least until the tire is broken in. The point of aligning a vehicle after a tire change is to help assure the new tires break in properly, and that suspension settling or shifting due to wear and tear is corrected before it has the chance to show up on the new tires.

So, in short, no, it doesn't matter on a stock car, with stock rims and tires, and stock ride height, and a competent alignment technician capable of correctly using the equipment.

TunerN00b

1) I was about to jump in over the "all intensive purposes" part, but was beaten to the punch.
2) The Pontiac Vibe is a Toyota Matrix.

ndiamondteague

I am a car novice customer but just googled this very problem and posted on FBook to my car buff friends, this very question. I just had my tires changed on my '07 Pilot at a reputable location that specializes in Euros typically. I picked it up and immediately noticed my alignment is off / has changed **or perhaps was just off before the new tires were placed and the tires adapted (I bought the car used from the dealer 1-2 yrs ago) I really want to know if these are independent of one another and apparently they are not. They have cause and effect. The man dismissed the feeling of misalignment to weather conditions and worked me back in 5 days out from now. However, I have to pull noticeably right when it steers off left 👎 even when I'm turning right (?!) I told him. I also requested a full detailed inspection during my service visit so wouldn't this have been checked? If so would it have falsely passed an alignment check with my old tires? Should they accept responsibility for cost of now having to realign so my brand new all purpose Pilot tires could have been jeopardized by unnecessary wear had I not mention anything? I'm just annoyed I have to bring it back for something it logically seems that should have been taken care of.... Anyone would notice this deviation of the wheel 😫 I'm a medical person not a car person but logic tells me tires should be checked to make sure things are ok AFTER the tires are placed since this can obviously happen? 😳

smilindave

This is a valuable lesson learned. Do not take your Honda to a shop that primarily caters to euro cars, your vehicle will not be treated the same as the euro crowd. I would find a shop that caters to their customers regardless of what they drive. I use one shop where I live for everything I cannot do or don't own the tools to do. These people always test drive after alignments. This is a must due to type of roadways in different areas, some possess more crown to shed water than others, thus "pull" for your car. Find a good shop that cares and you will have fewer issues with your car. It is akin to poor medical care, it could cause premature passing.
Regards
Dave