Oil Question

I just purchased an 860i. It is do for its first oil change. I called my dealer just to check to see if they had the oil and filter in stock. They had neither. I was told that the filter was transferable from another location, but they could not get the recommended JD oil. This boggles my mind a little bit. How do you more or less deny a customer, that just bought a brand new machine, the recommended product for the required maintenance. So, I asked the service desk if it would void the warranty if I ran a different brand oil that was the same viscosity. I was told it wouldn't. So with all of this being said, are there any of you the run a different brand of oil? Amsoil looks to be at the top, but expensive. Will it be okay to run a different brand of oil with the JD filter?


Thanks, Newt