I'm experimenting with a 97 Saturn SOHC 115,000 miles.
Pennzoil dino 5W30 1qt/1000mi
Mobil 1 0W40 1pint/3000mi, topped off, 1 pint/3000mi changed oil
GC 2000 miles so far, appears similar to Mobil
The LS1 engine is notorious for burning oil, but I don't need to add any oil in between changes to mine, the dipstick level does not move, even in 6000 miles. Same with my wife's Civic. Both are running GC.
Switching oils will result in consumption many times. We see people here have this problem in many cases. Some oils work better in some engines and some engines are not that tolerant to switching oils. RL was horrible in my Toyota for a 5k mile drain. But it's better then Mobil 1 in many LS1's.
I checked my records, and I have not added any oil since last October. Driving included a trip to the drag strip, some "spirited" street driving, parking for weeks at a time, and cold starts.
I don't think my consumption is excessive, so maybe the reason I used more GC than Pennzoil is the "cruel and unusual punishment" this particular batch has seen. This is my second GC run. Last time, I only needed to add 1/2 qt over 5500 miles.