So I’ve got a 2011 lml. I bought it a couple months ago with 77k miles on it, it’s now got 84k. I run it every day as my welding truck so it’s always loaded. About a week after I bought it I noticed it was a quart and a half low on oil but just filled it up and went on. It’s tuned and deleted so it was an as is sale so just had to grin and bear it. The consumption is all over the place depending on highway driving versus backroad 2 lanes. Made a 900 mile round trip and had to add a little over a quart. Hooked to a trailer hauling material I’ve seen it go thru a quart in 250 miles. It is head studded but have no way of finding out any history on the truck as to say what’s been done. No oil in down pipe, not enough blow by to knock the cap off laid upside down on the fill tube. Does not smoke on start up of a morning until you pull out and start getting up to speed, and then it’s only for about 10-15 seconds. I’ve not noticed any oil smoke while actively driving unless I decel. down a long grade then take off from a stop. I’m leaning towards valve seals but I don’t honestly know.