I have driven my 2008 Overland Diesel 100k miles. I change the oil w/Mobil One every 10K miles. Sears charges $109. Thats a penny a mile. My Subaru Outback I change every 3 -4K miles w/non synthetic oil. Sears charges $32. Thats a penny a mile. The oil filter is not easily accessible w/o a lift, and 10 quarts of oil makes a huge mess if you don't have an adequate catch basin.Just got my first oil change done yesterday, and about fell over when I looked at the receipt and saw it was $177. How long can I expect to go between full synthetic oil changes? Also is it wise to just change it myself going forward and save a couple bucks? How will this affect my warranty if I change my own oil?