Oil use is designed in to avoid lube issues at high rpm, they can turn 7000 rpm in the STS, they have very aggressive cross hatching on the cylinder walls for that purpose. they hold 8+ qts of oils and aren't considered low until around 5-5 1/2 qts when the low oil light will come on. This is the same method used by many exotic builders. They're safe to drive down to about 4.5 qts. These are sophisticated engines and generally poorly understood and even m,ore poorly maintained by the average used Caddy customer. They require complete coolant flush and refill about every 30k miles and you must us the GM additive or they can toast the head gaskets, that's the number one cause of the corrosion that causes the head bolt/gasket issues with them, not poor design or build quality.

 

You're too kind... Actually the current Caddy horns are for my HHR..

 

Better not use them Longhorns then, better get some off a milk cow!