So, driving set on L7 SEEMS like it might turn the DFM function down if not off. I can clearly notice the DFM on my truck at 1300 rpm with light throttle. Feels like a cell phone on vibrate ringing in the center console. I even took it to the dealer to have it checked out because I thought it couldn't possibly by normal. Of course they told me it was and that I was "essentially feeling a miss-fire". I am not sure I buy that, but either way when I put it in L7 I don't feel that. Now I didn't have a long drive, but in D I can make it go in DFM on command. If it was there with the L7, it was so much more subtle it was undetectable which is the way I understood it should be. So I won't say without a doubt the DFM function isn't working at all in L7, but if it is I sure can't tell. What I'm curious of is if maybe it is working but just not dropping as many cylinders so I can't feel it. Dropping down to 2 or possibly even 1 cylinder (I think I read that) is a bit drastic for a V8. Personally I want all 8 all the time. I paid for a V8, so I don't understand why it's not even an option to me whether or not I want to use this function.