It depends on your driving habits. If the car is serviced as required and the oil changed every three thousand miles, and if the car is driven under normal circumstances, the answer is only as long as you take care of it. I have done this with cars that I own that have over two hundred thousand miles and running strong. Your question is your own answer. Of course I live in the south with no snow or ice treatments that can destroy the car before its mechanical failure.
The 2008 Cadillac CTS has 24 valves.
The 2004 Cadillac CTS has 24 valves.
The 2006 Cadillac CTS has 24 valves.
The 2007 Cadillac CTS has 24 valves.
The 2005 Cadillac CTS has 24 valves.
The 2010 Cadillac CTS has 24 valves.
The 2009 Cadillac CTS has 24 valves.
The 2014 Cadillac CTS has 16 valves.
The 2003 Cadillac CTS has 24 valves.
The 2011 Cadillac CTS has 24 valves.
The 2013 Cadillac CTS has 24 valves.
The 2012 Cadillac CTS has 24 valves.