to answer the questions from ben1364. My 2005 cdi now has 18000 mi since march and it is a straight six. It does have a dipstick tube but no dipstick. There is a plastic plug in the hole. At the dealer, they suck the oil out here. A Ford econoline dipstick obtained at a junkyard for about $3.00 will work once the markings are figured out. In addition, the refill quanity in the owners manual is wrong. It should be 7.9 quarts (8), not six like it says. On a trip to colorado, I averaged 35.2 miles per gallon. I generally drive at the speed limit or one mile under.