I have a 2017 Chevy 1500 lt with 111k on it my gas mileage as been just dropping I'm average miles per gallon on highway is 14 I average about 9 in town I don't constantly floor it but when I first got it I was getting mid 20 on highway and I've noticed a drop in power and clunking in the rear when I back up in snow I have replaced shock in struts dose clunk when i hit pot holes sometimes the last time I changed the oil there was alot of shaving in my oil