I have a 2006 V6 (non AWD) with 22,000 miles. My experience:
The car holds 6+ quarts when fully drained. This is up to 1/2 quart more than other member's experience. The oil pan on an AWD may be different and reduces capacity in that vehicle.
My car does not use oil.
I have no oil leaks.
Engine does not have any unusual sounds.
I changed the oil at 3k miles, 8k miles and at 16k miles
Mobil1 turns black by 8,000 miles, at which time 33% life is left showing on the indicator. I typically change any oil before it turns black.
Not all synthetic oils meet GM's standard. Read the label.
Castrol SynTec begins clearer than both Mobil1 and Royal Purple. I have no experience with Pennzoil Platinum.
I have a trivial amount of metal on the magnetic drain plug I installed as a replacement for the stock drain plug. This is typical of many engines but unnerving to most people. If it changes or consists of larger particles, I would be concerned.
A stuck PCV valve on an engine will commonly cause the crankcase to pressurize the engine and force oil out as leaks. I don't know anything about the SRX's PVC valve but see the discussion at
http://www.cadillacforums.com/forums...-requires.html.
The owner's manuals for certain Mazda's, VW's and Audi's claim the consumption of 1 quart of oil per 1000 miles is considered normal for these cars. I know some drivers who experience this; others did not. Some service managers claim the statement is purely PR to lower the purchaser's expectations. I would rather know the facts.