Question, i recently had my car in for an oil change and was down half a quart. Granted half a quart isn't much at all, but my question is is it normal for the ecos to start using oil after 100k plus. First time in the 5 yrs i've owned the car, that i've ever been down at all between oil changes until this point the oil level has always stayed full. Looked around underneath didn't see any visible leaks anywhere, just coming from 5 yrs of never being down at all to suddenly being down surprised me.

Hey Bill, I have a stock '05 Ion quad coupe 2.2 thats at 70,000 miles & has not used any oil.
for the past 2 years I've used the Amsoil Signature Series 0W-30 100% Synthetic Motor Oil & follow their & GM's extended drain plan.
I use a Wix oil filter & change it every 3,000 miles. I average 12,000 miles per year and get a consistent 32mpg driving highway/city driving in Boston suburbs.
I've been reading about Ecotec 2.2 timing chain failures usually after 110,000 miles.........don't know how real this failure rate is??

Good to know mike, since i have 135k on the clock now