Newer Cadillac's have a display in the dash area showing "Oil Life" expressed as a percentage, it will typically go to 10,000 miles before showing an oil life of 0%. There is also one for the transmission fluid. "An industry first in new vehicle features, this oil probe can determine and detect the actual level and remaining engine oil life. It can reduce the need for costly engine repairs due to poor oil maintenance as well as prevent unnecessary oil changes." This was from a plug for a 2005 STS. Interesting, Dan Elliott 82 300D-T 84kmi
