My local dealer informs me that Stihl will double the warranty time period if you buy a 6 pack of their synthetic oil at the time of purchasing the Stihl tool. I was looking at a leaf blower with a 2 yr warranty but would extend to 4 years with the 6 pack. Decent deal I think, but you have to buy the oil at the time of purchasing the tool. I forgot to ask, but have they been offering this for awhile?