Manufacturing variability could theoretically do it. Or your oil pan could be dented slightly. Or you might not be measuring as exactly as you think. Or some oil could be staying in the pan when you drain it. Or a combination of some or all of those. There’s very little difference between 4.5 and 4.8 quarts (~6%). Bone dry with a new filter you should be able to put in ~4.8 qts, then run the engine for a minute, and then add another .2 qts, so the difference between the theory of what should go in and the reality of what you’re seeing is pretty insignificant. As long as the dip-stick is reading full I don’t think there’s anything to worry about.But after reading my posts, and knowing that I've been doing this since the early 2000s, what could the possible reason be? Someone @the factory used an oil pan from some other production run? My 4 and1/2 brings it right up to the full line. Are there any other strange birds out there? Is puzzlement!
You’re welcome. I don’t always like WikiHow, but this is pretty solid and should help you find the serial number: How to Identify a Ford MotorYes, the Kwik change guys (they're using ecogard oil filters) and blended synthetic oil. I've usually changed oil before the 3k mark 'cause in many situations especially cold weather, I'd be idling just to keep warm, out by myself, watching independent contractors as my assignment (working for a railroad, watching outside contractors so they made it home uninjured. Last time was mid 1990s, when they were using directional boring to bury empty, flexible pipe, for future fibreoptics.). So, cold weather change oil way before 3k. Again, not 5 quarts? Tis a mystery. Perhaps engine was changed out years ago..?? I've had it at least 16-17 years, and have done, when I was younger, actually done oil changes myself, so this is a genuine mystery. No accordian pleats in the pan, this seems to be an earlier, pre-1997 engine, and I'll keep giving it the required TLC as best as possible. There's something going on here, if I had stumbled across this soon after I bought the car, an explanation may have been possible. Is there an engine id# somewhere on the engine? Still until I can get Sherlock interested, fat chance. I'll keep up keeping up, and shaking my head at the advancing rust that will force me to find another ride.
Thank all of you for the feedback and helpful info, don't forget to replace front end parts @ 90k! better than being stranded, and the usual (large) towing fee. Remember 6 of 7 resistance or denial is futile!!
Cheers, and once again, thank you- from a newbie, however you spell it!