As others have reported here, and on other forums, the oils consumption was remarkably high. I always tolerated it, because otherwise I loved this car. I vas very fastidious about keeping the oil level at an acceptable point. During cold weather in March of 2011, It went from near perfect performance to a very rough idle, and a host of P codes. Close inspection revealed that the plenum had cracked, and was causing a major vacuum leak. The mechanic at the Cadillac dealership near my home revealed that it was a very common problem with that motor.