I just bought a used SRX, a 2006 with 40,000 miles. My concern is the amount of oil this uses up between oil changes. I have had it changed for the second time now, and it is consistently at least two quarts low between 3,000 intervals. There are no leaks that I can find, no smoke out of the tail pipe to indicate it is burning, and no evidence of blow-by. Has anyone else experienced this? Is this what I should expect from using synthetic oil? What should I have checked?