Thats a tough one to prove.
They can't force you to use their oil and void the warranty. The oil you use may have to meet their specs (which isn't hard to do.) And you may have to prove it needs their specs but beyond that, the law is very clear on that subject.
Where might you find the language that specifically says it would be against the law for them to enforce usage? I have the same essential question/concern: I dont mind the point-of-sale upsell to their oil, but the using it might be another matter.....
Just kind of reading along in this thread and I'm quite amazed the Stihl warranty periods are so short. Like they have no faith in the products. I'll stick with my Echo saws and brush / weed trimmers. 2 and 5 on everything, no exceptions. Having said that however, I've never had a warranty issue in any of the saws I've owned or own presently.
I have not found that the warranty length has any correlation to how long a product would last. Many sellers require that you produce the original receipt and are counting on the fact that most people will not keep them or may lose them. Also, many warranties are pro-rated. That is, if you have a 2 year warranty and the product fails after 23 months, you get a credit of 1/24th of the original purchase price towards the purchase of another identical or similar product. The Sears Die-Hard battery is a case in point. I never had one that lasted the warranty period. Most died in less than 2 years. I finally quit buying them and found that the Everlast batteries at Wal-Mart were actually better. I get 5-7 years out of them usually. As for my StihlMS500i, I bought the Stihl oil to get the two year warranty, but I do not intend to use it. I will be using Amsoil exclusively.
The Magnusson-Moss act.
I don't think it does violate that act. The basic limited warranty does not require the use of Stihl oil. The extended warranty is granted by the purchase of Stihl oil, but there is no requirement to actually use that oil. Moreover, that act applies only to normal consumers, not those who use the product professionally or for profit. https://www.ftc.gov/business-guidance/resources/businesspersons-guide-federal-warranty-law
That's exactly what I was getting at. A mfg can't deny warranty based on you not using their branded oil.
And Stihl is not denying the warranty based on the use of their oil or not. You get the standard warranty regardless of whether you purchase their oil or not. But if you buy their oil, you get an extended warranty. In essence, you are purchasing the extended warranty by buying the oil. I just wish I could find something useful to do with my Stihl oil. I sure as heck will not put it in my chainsaw!
I think everyone understands that.
