You are 100% correct about GM. I had a 2007 Yukon XL with the 5.3 engine. It started to use 1 quart of oil every 1000 miles once i hit 36k. I brought it in a bunch of times to the dealer and they said GM says that was normal oil consumption. Which is complete BS! The 2007 -2009 models were so bad that GM doesn't offer a replacement crate engine for those years. I traded it in in 2016 for my 2014 Ram 1500 Quad Cab and couldn't be happier with my truck. I get 16-17 mpg local. I just did a 4300 mile trip from NJ to Colorado and back for an elk hunt and averaged 21.3 mpg and have gotten up to 25 mpg on flatter slower speed trips. The best the Yukon ever got hwy was 18 and usually 14.5 local.