The XFire 3.2 liter V-6 actually requires 8 liters for an oil change - it is after all a M-B based product. That turns out to be 8.45 quarts. Like others, I always add 8 quarts back during an oil change. I do this because the 1st time I did an oil change, I added the 8.5 quarts. We then went to a XFire ToD weekend event a few weeks later and the warning light for oil overfill kept coming on during the ToD runs. I'd rather be slightly under than over.