 At little over a year, performance and gas mileage began to deteriorate.Next, an engine knocking became increasingly loud.no check engine or oil pressure light warning.Dealer found oil 3 quarts low-- suspect that the engine had already been damaged..on investigation, this is a systemic problemwhich Hyundai Equus and Genesis with the same engine share.Hyundai does not appear ready to own up to the defective engine which occurred with the higher horse powered 2012.Major blow in their aspirations to compete as a luxury brandupdate: they have pulled the plug on the Equus brand;won't fix hardware breakage under warrantyUpdate :after lots of aggravation they finally replaced engine and it been a good car with bad service