I have a 2005 Cobalt 2.2L that is currently burning 1 quart of oil every 850 miles. From what I understand, 1 quart every 2,000 miles is fine. I'm doing over twice that amount. There are no leaks as far as I know. There are no puddles under the car. There has never been any smoke from the exhaust. Anyone know what might be happening? Thanks!