I disagree. I see nothing in the M/M info on the FTC site that indicates non-licensed products are excluded from coverage of the law.
Using an oil that carries no certification still falls under the M/M ACT. It just may or may not make it more difficult to defend against counter-claims of unsuitability.
Example 1:
If you choose to use a non-licensed engine oil (let's say Amsoil or HPL) in your engine, that does not mean that the warranty of the engine is automatically void. It only places the burden of proof upon the lube maker to prove that the lube is suitable for the intended application. Producers of high-quality products which are intended for the application will likely be able to show that their unlicensed product is still viable for that application relative to the license spec/standard.
Example 2:
If you choose to use a non-licensed engine oil (Amoil or HPL) in your differential, that also does not mean that the warranty of the differential is automatically void. But it certainly makes it way more difficult to prove that the lube chosen would be defendable. And even the lube maker may void their warranty if you use a product in an application it was not intended for.
The key is that any product, licensed or not, has to be proven that it "caused" the failure. Here is the specific language form the FTC:
"
Companies may, however, refuse warranty coverage for defects or damage caused by using third-party parts or third-party services."
The issue is the concern of proof of the root cause of failure. Just because something is unlicensed does not automatically make that product the cause of failure. It has to be proven it was the cause of failure. M/M is still in effect; it makes no determination of license status relative to the applicability of the product and warranty.
And in fact, licensed products can still be the root cause of failure. Just because something carries a license does not mean it was properly made to that specification/standard. A licensed lubricant could fail to meet the standard via production problems; a lube could have the wrong additive package, etc. Hence, even a licensed aftermarket lube which caused failure would be a reasonable cause to deny warranty.
Licensed products make for a higher level of confidence when using a product. But licensed products are minimum standard, not a maximum standard. And those licensed products are not fool-proof; they can still cause problems. And unlicensed products are not automatically implied to be at fault; that's a misrepresentation of the M/M conditions.
The M/M Act is law that essentially states how warranties are to be offered, described and implemented.
The law does NOT automatically assign or deny the root cause of failure based on license status.
https://consumer.ftc.gov/consumer-a...-companies-warranty-restrictions-were-illegal
https://www.ftc.gov/business-guidance/resources/businesspersons-guide-federal-warranty-law
