I have a 2011 5.3, I use it for work (Meter Reader), I do have the AFM dissabled, I currently have 114k on the truck but the motor has really high hours on it, I am at 4450 hours on the motor now, I change the oil at 5k intervals and is not using a drop to this day and is still running really strong.I hope to use this truck for 2 more years at which point it will have close to 250k on it and well over 8 thousand hours, should be intresting to see how it is running then or if it even makes it that far.As it is right now the engine has more hours on it than an average daily driver would at 300k. It seems to be a very durable engine.