I think 2 things can account for oil usage: the oil and the engine. Seems obvious, but take this example: My mother-in-laws A6 1995 V6 consumed tons of oil with Mobil DCO and Valvoline, 1q/2000mi. With GC, M1 0w-40 and 15w-40 HDEO, consumption is nill. 1q/5000mi is outstanding in this engine. So in fact, the oil itself is to blame in this case. In a beater that has a bad oiling system and wear, consumption will be high no matter what kind of oil you use. Obviously, in a chug-a-lug car, a super-thick oil would diminish consumption over a high-quality thin synth that works fine in tight engines. Two different issues at play here.