Filled up today and checked the oil. Yikes! below "Low". Didn't have any synth at home so try and find and open store on Thanksgiving Day. Had to spend $14 at a BP for 2 quarts, and that didn't even fill it up. Had oil change less than 5000 miles ago, first time w/ synth. Meant to change it earlier than 5K, but got busy. Checked the oil probably three tanks ago (about 900 miles) and level OK. Where did the stuff go? Not a drop on my garage floor (just cleaned out the garage yesterday while the cars were out and my parking spot nice and dry). Hope nothing bad happens for running low. Oil pressure light never came on. I'm checking under the hood every fill up from now on. By the way, I only have about 18K on the truck now and have never had a problem in the past w/ keeping oil in the crankcase.