Many consumers mistakenly believe that they must use manufacturer-approved parts so as not to void their warranty. The manufacturers might want you to believe this but nothing is further from the truth. Aftermarket replacement parts will not void your new car’s warranty. However, modifying or tuning your car might run afoul of your car’s warranty coverage. Here’s what you need to know.
Warranties on consumer products are governed in the U.S. by a Federal statute known as the Magnuson Moss Warranty Act. This Act spells out what warrantors can and cannot do in connection with the warranties they provide with their products. While the Act applies to everything from lawn mowers to dish washers, the place it has the most impact on the average American is with the warranty that comes with a new car.
And the Magnuson Moss Warranty Act specifically forbids manufacturers from forcing consumers to use name brand parts on their vehicles.
No warrantor of a consumer product may condition his written or implied warranty of such product on the consumer’s using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty) which is identified by brand, trade, or corporate name . . .
Notice that the manufacturer can require the use of its parts when it is providing them to you free of charge. The Act also allows a manufacturer to apply for an exemption if it can prove that its own brand part is necessary. This is rarely the case.
Still, I get asked from time-to-time if my interpretation of this section is correct. Don’t ask me; let’s see what the Federal Trade Commission says. The Act specifically empowers the FTC to interpret the application of the Act and on its own website the FTC has a section addressing auto warranties.
In response to the question, “Do I have to use the dealer for repairs and maintenance to keep my warranty in effect?” the FTC replies:
No. An independent mechanic, a retail chain shop, or even you yourself can do routine maintenance and repairs on your vehicle. In fact, the Magnuson-Moss Warranty Act, which is enforced by the FTC, makes it illegal for manufacturers or dealers to claim that your warranty is void or to deny coverage under your warranty simply because someone other than the dealer did the work. The manufacturer or dealer can, however, require consumers to use select repair facilities if the repair services are provided to consumers free of charge under the warranty.
The question that comes next is, what about someone who has tuned or modified their car with aftermarket high-performance parts? Can the manufacturer deny my warranty coverage for something like that? Yes, they can. Of course, it depends on the modification and what the failure was.
The Magnuson Moss Warranty Act says the manufacturer cannot force you to use their parts but they also do not have to pay for warranty repairs caused by someone else’s part. Or, if your part caused something else to fail. Like if you put a monster turbo on your car which did not come with a turbocharger in the first place. The Federal Trade Commission addresses these things as well:
Still, if it turns out that the aftermarket or recycled part was itself defective or wasn't installed correctly, and it causes damage to another part that is covered under the warranty, the manufacturer or dealer has the right to deny coverage for that part and charge you for any repairs. The FTC says the manufacturer or dealer must show that the aftermarket or recycled part caused the need for repairs before denying warranty coverage.
So, if your hopped up car’s radio stopped working, the manufacturer would have to pick up the repair so long as there was no connection between the turbo installation and the radio operation. BUT, if your turbocharged engine now put too much power to the transmission and the transmission failed, then they could deny the coverage on that repair.
People often say they have been told that if they modify their car, their entire warranty will be voided. That is never the case. But the warranty on a particular part or system damaged by your modification might be denied.
It must also be pointed out that some of these are judgment calls. Did the modification cause the failure? If the dealer or factory rep says “Yes,” you will have to argue with them to make your case. If they don’t budge, then the only way to force them to do something might be litigation. And that is never easy, swift or cheap.
Next time you are looking under the hood of your car and considering replacing routine maintenance parts, feel free to shop around. You can use the parts the dealer sells if you want to, but you’re free to go with the less expensive stuff from the auto parts store as well. As for modifications to the car, be careful. It’s possible that a failure related to the modification might not be covered by warranty.
Steve Lehto is a writer and from Michigan. He specializes in Lemon Law and frequently writes about cars and the law. His most recent books include , and . He also has a where he talks about these things.