I have a 1999 C230k which I purchased new in 1998 when the kompressor engine was new in that model. It now has 145,000 miles on it has been a very reliable car, except for the supercharger seizing at 100,000 miles. For the first 80,000 miles it used conventional oil and went about 10,000 - 12,000 miles between changes before it was switched over to Mobil 1. The engine has a distinctive noise at slow speeds but is quiet otherwise. It has a lot of power (more than the C280 in my opinion). A very solid, reliable car.