Will changing size of wheel and tire void manufacturer warranty?

I think seat covers could interfere with some airbags that are mounted on the side of the seatback in some cars.


I used to work in the warranty department of a major tire manufacturer, while IANAL, I spent quite a bit of time with the company attorney trying to understand how warranties work.

First, warranties are written by attorneys. They are carefully worded to delineate what is covered and what is not - including circumstances. For example, racing a car is an automatic denial.

As was pointed out, almost anything can be used to deny a warranty - HOWEVER - the denial has to include why the coverage is being denied. The company doesn’t have to PROVE it (at least, not yet!), just identify why.

The burden then shifts to the consumer. If they think the warranty denial is not valid, there is usually something in the warranty that covers appeals. At that point, the consumer has to follow the procedure outlined and provide expert testimony. Needless to say, the company denying the warranty has an expert who will testify. Then it becomes a matter of which expert is more credible.

In this case, it is common for tires to be replaced during the term of the warranty. So the issue becomes: Is there something about the tires that would cause an issue that could be traced to the change of tires - and there is hardly anything that changing tires is going to cause to go wrong - and the company’s expert would say so to the company’s attorneys. That used to be my role.


But he is asking about changing the wheel and tire to non-OEM specs:


If anything fails in the steering rack, front suspension or wheel bearings, I could easily see them saying- you installed different wheel/tire combination and this created more stress on these parts. Denied. Now how are you going to prove it didn’t?

Worse yet, you get into an accident, the lawyers start with the “it’s modified from original design…”.

I have a lot of tolerance for risk and wouldn’t get too worried about making changes but not everyone has that same level of tolerance (or perhaps even experience to gauge the risk involved).


Great point.

How likely is this? Seems like it would take a lot to convince that a slight modification in wheel size caused an accident. Had this happened to you or someone you know?

I think that will depend on the severity of the accident. If there are personal injuries, I think they will pursue any avenue and your own insurance is likely to step back from covering the car or you as well in the case of large settlements. You can google “liability for vehicle modifications” and see plenty of information you can weigh in your decision. Yes, I was in a very serious car accident many years ago and during the deposition, there were all kinds of questions regarding this topic as well as due diligence to mitigate personal injuries. I was the injured party. They were looking for any avenue to leverage…

So the probability is very low but the risk is high.

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Correct. If the seat covers interfere with the mechanical function of the seats, then it can (not will) void the warranty. But if there aren’t airbags or anything else the covers can interfere with, then the warranty can NOT be voided.

Even though Magnuson-Moss Warranty law is in effect, many dealers will tell their customers that any part replaced on a vehicle that’s NOT from the dealer will void the warranty. It happens to this day. I was told it by a Toyota dealer less than a year ago.

A former Mechanical Inspector here. In reality, it has nothing to do with whether alterations caused the problem or not but every warranty contract has a provision that states “alterations void warranty”. So it’s not the matter of expert credibility but rather who has more money to feed the lawyer. And the company usually wins.

Absolutely sounds like the reality I know and live in lol. Deepest pockets means mostest rights and freedoms.

So if the Seltos model I have has both the 16" wheel and 17" wheel listed in the manual, I could switch to the 16" wheel and it technically wouldn’t be an alteration, right?

I can’t speak for all manufacturers - most likely it’s not the case with all kinds of fords because they are not concerned about details but with Toyota, different wheel sizes may come with different rotors. In my case, larger (17" rather than available 16") tires came with smaller rotors which makes sense - larger wheels need lower breaking force. This could (COULD) be grounds for denial. Reasonable or not, legal or not but get ready for fight.
On my last honda (2004 CRV MADE IN JAPAN!), an injector went out @34,000mi, and the stealer attempted to deny warranty on the grounds that “injectors are not covered”. Note: they knew me - I did a lot of inspections there not to mention bought a few cars but they still attempted to screw me over. In fact, not only injectors are covered under 36/36 warranty but also under 60/60 federal EPA warranty most people don’t know about. I just asked the service guy to write it down and sign. All of a sudden, injectors became covered, and they replaced all four “out or precaution”.
Bottom line: do not expect fair game.

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Exactly why I’m considering waiting until my 100k mi warranty expires.

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Did you find it out? I think that changing the size of your wheel and tire could potentially void your manufacturer warranty. To be sure, it’s best to address the manufacturer or someone who already dealt with it.

We drive a 2020 Connect which started out with 16’’ wheels and 215/55/r16 tires… In the two years of ownership we’ve upped the wheel/tire size to 19’’ w/ 245/40/r19 tires. So I would assume that if that voids out warranty, we complete blew that out of the water with that much of a size increase.

And what was wrong with the factory wheel size in the first place?

(If your response is “looks”, that’s an invalid reason)

The van handles better more stable when cornering assuming one has the correct tires like we do.

Federal law prohibits manufacturers from conditioning the warranty on the use of any specific OEM part. In other words, the warranty cannot be voided solely due to the installation of aftermarket parts. It’s called the Magnuson-Moss Warranty Act and it’s been around for almost 50 years. Of course, if it is determined that the aftermarket part caused the damage, then the warranty claim can be denied.


I am well aware of the Magnuson-Moss Warranty Act as we’ve been a loyal K&N product user for many years till now…

I love the English language. The original question was “Will changing …” And the answer is No!.

But like the quoted words say: The warranty could be denied by changing …

That means that the real answer to the original question is “Maybe!”


Here are some ways non-stock wheels/tires could void a portion of the warranty:

  • Wheels have different offset than stock, stressing suspension/bearings

  • Wheels are much heavier than stock, stressing suspension/bearings (4" bigger than stock, for example)

  • Wheels are much lower profile than stock, stressing suspension/bearings (30 series, for example)

  • Staggered wheels/tires don’t match stock, causing problem with AWD or ABS


The correct tire and pressure for it are provided by the vehicle mfgr.

We’re not riding on the correct tire size in the first place. so the numbers on the door jam are irrelevant.