I just bought a Husqvarna 224L trimmer, and I am working on warranty information for this. Apparently I have to buy 3-32 ounce cans of premix fuel to extend the warranty an additional 2 years. How does this make sense? I bought a 4-cycle trimmer, but have to buy a whole lot of premix fuel to get the warranty. Is there anyway to get around this, saying that its 4-stroke?