Will Performance Modifications Void The Warranty?

[A/H] The warranty manual on all of your NSX’s specifically states that the warranty will not cover: Abuse or misuse… Use in competition or racing events…any failure caused by modifying the vehicle…
Please Understand: The Warranty is voided NOT when the part goes on the car but WHEN AN AFTERMARKET PART CAUSES SOMETHING ELSE TO FAIL. When an aftermarket parts maker/distributor promises you that installing a part on your car does not void the warranty they are correct.
I like RM, Comptech, etc., and I wish I could put some of their parts on the cars I drive, but don’t be fooled by their promises. Comptech may be developing something for American Honda, but if the car fails, American Honda will not be going back to the factory that built the car to have them pay for the failure under warranty. (Yes each factory pays its own warranty)
Please enjoy your cars, they are great toys, but please accept the responsibility when it may cost you $$$.
[GM – 98/12/16] I recently had the opportunity to discuss NSX warranty issues with Mr. Will Owensby, Acura’s Zone Manager for Parts and Service in the Southeast region of the USA. Please note these comments are my interpretation of Mr. Owensby’s comments and are intended to reflect Acura’s position on general warranty claims. This post does not address any specific NSX warranty situation including those currently under discussion with Acura. I am writing this as a concerned NSX owner and member of the NSX owner community, and not in any way representing the American Honda Motor Co. or the NSX Club of America. These are my interpretations of meetings and conversations held with employees of American Honda and should not be construed as American Honda’s policy.


The NSX was tested extensively before it was released. It was driven on public roads as well as racetracks around the world by many professional drivers. Acura found that aside from installing new tires and brake pads regularly there were no problems with the NSX design when used in this manner. There were no engine failures when OEM cars were tested in this way – none.


Putting an aftermarket part on your Acura vehicle does not void the warranty on that vehicle, but Acura does not warrant anything they do not manufacture. Look at the tire warranty that comes on new NSX’s – that is a warranty supplied by the tire manufacturers, not the vehicle manufacturer. However if aftermarket parts create a condition that causes the vehicle to fail, that failure may not be covered under your vehicle’s warranty. Let me outline this important point by way of example: Say you add a supercharger to your NSX. This product makes additional engine power, but it does that by increasing the heat, pressure and stress inside your engine. If this increased stress causes an internal part to be operated outside of its design limits and if that part then fails due to being operated in that manner, your Acura warranty may not cover the failure. This does NOT mean your warranty is void – you still have a fully functioning warranty, but Acura may take the position that this particular failure is not due to their actions so they will not cover the repair of the failure. Another way to say this is that the Acura warranty covers failures due to defects in the design and manufacture of their products but if the failure is due to an outside cause the warranty may not cover that.
The above means that Acura or Honda do not warrant anything made by any aftermarket manufacturer. An independent Acura dealer may offer to stand behind an aftermarket part that they sell to you or install on your vehicle but that is a separate issue from the warranty offered by the manufacturer of that vehicle.


The Acura warranty is very specific in stating it covers vehicles that are designed to be used on public roads and operated at the speed limit. It also applies to vehicles operated in North America only. However Acura takes a very generous view of these conditions. There have been many Acuras sold to service people who were then transferred overseas. If your Acura fails under these conditions you technically have no warranty coverage (coverage is limited to North America) but Acura has never denied a claim under these conditions. Similarly if you use your vehicle on a racetrack you have not voided your warranty even though the document states the vehicle is to be operated on public roads. Acura has fixed cars that have broken at the track. However, if you are constantly operating your vehicle on a racetrack or if you have modified your vehicle to produce more power (and stress) then you are operating your vehicle in such a manner that the systems in it are being stressed more than they would be in normal street use. Therefore a prudent owner should take precautions for this increased stress. A recent post from Comptech via Chris Nelson outlined
some of these precautions.
I’d like to use an example to reinforce this point.
Would you buy a consumer appliance and then operate it in a commercial environment and expect the manufacturer’s warranty to cover all failures? I don’t think so. We all realize if a washing machine has a 10 year warranty designed for 7,000 cycles (say 2 loads a day for 10 years) and it is used in a place where those cycles will be used up more quickly (say 10 loads a day in a commercial facility) then the product may fail in only 2 years instead of the 10 years that a consumer might expect. Should the manufacturer’s warranty cover use like this? Furthermore if the machine fails after 2 years in commercial service, should the manufacturer then be accountable for a failure analysis and be forced to supply an engineering report on why the machine failed? I don’t think so. I think the person who decided to increase the duty cycle on the machine must take the responsibility for the consequences of that decision.
Driving on the track is similar to the above example in the eyes of American Honda. If you drive in that environment you are accelerating the wear and stress you place on your car. You should take precautions for the survivability of your car and its systems. These would be precautions like using the best fluids you can find in your vehicle and keeping them clean and fresh, being aware of the altitude and ambient temperature you are driving in and perhaps adjusting the spark plug heat range to these conditions, and other similar precautions.


Honda’s research has shown repeatedly that use of an aftermarket air filter results in more grit being drawn into the engine with consequent increases in ring wear. It doesn’t matter if your vehicle is a Civic, an NSX, or a Honda motorcycle – you will decrease the life of your engine by using a less restrictive air intake system. The failed NSX engines that Honda has examined all show signs of significant ring wear – wear that is not consistent with the mileage on the vehicle. All these engines also had aftermarket air filters. I asked Mr. Ownesby why there were cars fitted with aftermarket intakes that had high mileages and had not suffered any breakdown. He referred to the fact that these units are purchased from 3rd parties and usually installed by the owner. They are made of rigid pieces connected by flexible pieces and held together by hose clamps. Maybe one owner installs his in such a manner that it leaks and lets unfiltered air into the engine, while another installs his unit correctly. Referring back to the coverage of the Acura warranty, why would Acura warrant something that they did not design, do not manufacture and did not install? That’s an easy question to answer – they don’t warrant these parts, the manufacturer does. So who is responsible if an owner installs a part incorrectly and his engine fails? If the aftermarket part was made correctly with no defects, and if the failure of the NSX was not due to any defect in the design and manufacture of that specific part, then the owner, who bought and installed the part, has to take some responsibility for the failure.
This should be seen as a reality check for NSX owners – you just can’t do anything you want to your vehicle then drive it in any manner you like and expect Acura or anyone else to pay for the damage if something breaks. If you don’t agree with that statement I have a question for you: Do you think you should be able to modify your NSX in any way, and then drive the car in any way, and have the manufacturer pay for any damage that might occur? If not, please tell me where you draw the line. It is this stage that is not a black or white situation but a gray area.


Honda sees a tiered system of warranty coverage and owner responsibility as the fairest and most honest way to look at vehicle failures.
Let’s say you keep your car stock – Honda is confident that you will have no problems with your NSX, period. If you do have some kind of rare failure, in all likelihood they will fix the problem for you under the terms of your vehicle warranty.
In this scenario perhaps you have modified your car slightly and drive it on the track occasionally. Again Honda is very confident in the design of their car and in all likelihood you will have no problems with your NSX but if you do they will most likely fix the problem for you under the terms of your vehicle warranty.
In this scenario you have modified your car extensively and / or drive it on the track in a very aggressive manner and take part in many track events each year. It is at this point, that is admittedly hard to define (see gray area above) that Honda believes an owner must start to take some responsibility for damage that may occur to their vehicle.
I think people who fall into the third category should be aware of this responsibility. By modifying and using their vehicle in this manner they in essence re-engineer the car and change the operating parameters from those which the vehicle was designed for. American Honda cannot be responsible for these changed conditions or increased duty cycles. The owner in this situation should increase the maintenance on their vehicle in line with the Comptech recommendations posted by Nelson. They should think about buying a leakdown and compression tester and use it after each event to judge the condition of their engine, especially the rings. They should have their oil analyzed at each change as well as any other reasonable precautions they can think of.
Please note that Acura has in the past and may in the future still provide partial coverage under such circumstances; even though their position is that warranty coverage is not required. Such partial coverage would be done as a goodwill gesture.
The NSX is one of the most complex vehicles ever made. The interaction of its systems are subtle and not easily understood. Things that seem intuitive may not be. Modification of the vehicle risks upsetting some of the checks and balances incorporated into the vehicle’s design.
If you modify your NSX you must think carefully about what you are doing, what it affects, what it might affect that you don’t know about or cannot easily see and the responsibility you may be creating for yourself if something breaks. Of course we can all cite illogical examples that don’t follow this reasoning – you buy an aftermarket muffler and your stereo breaks. But if you get into some of the gray areas mentioned in this post you may be changing the vehicle sufficiently or using it in such a manner that you may be responsible for any failure that may occur.
I want to reinforce that I am writing this as a concerned NSX owner and member of the NSX owner community, and not in any way representing the American Honda Motor Co. or the NSX Club of America. These are my interpretations of several meetings and conversations held with employees of American Honda, and should not be construed as American Honda’s policy. Please address all complaints or concerns about NSX warranty service to Acura Client Services at 800-382-2238.

Warranty Exclusions Text

[From the ’91 NSX owners manual]


The warranties in this booklet do not cover:

The failure of any part or accessory due to: 
Abuse, misuse, accidental damage, or acts of God. Improper installation or maintenance. 
 A low fluid level, or the use of a fluid other than specified by Acura. 
 The installation of any part that is not equal to the original in quality or workmanship. 
 Use of the vehicle in competition or racing events. 

Any installed part of accessory that fails because it was not designed to fit that year and model of Acura. 
Any car with an odometer that has been altered so it is impossible to determine the actual miles. 
Any failure caused by modifying the vehicle, or installing accessories not authorized by Acura. 
Any incidental expenses or inconvenience you may suffer due to the loss of use of your car. 


This Warranty Does Not Cover:

Emission control systems, accessories, battery, or tires (They are covered by their own seperate warranties.) 
Normal wear or deterioration of any part. 
Cleaning and polishing. 
The adding of any fluids, unless they are needed as part of a warranty repair. 
Air conditioner refrigerant charge after the first 12 months, unless required as part of a warranty repair. 
Glass breakage and/or scratches that are not due to a defect in material or workmanship. 
Any item having to due with your car's general appearance that is not due to a defect in material or workmanship. 
The replacement of expendable maintenance items (such as spark plugs, filters, wiper blads, or brake pads/linings) 
 [unless they are defective in material or workmanship.] 
Wheel balancing and wheel alignment after the first 12 months, unless required as part of a warranty repair."