1 Gal Delvac 1 + 10,000 miles = .75 Gal???

I did my 50,000 mile maintenance yesterday ('03 Golf TDI). I had been using Valvoline premium blue extreme oil for the first 40,000 miles, so this was my first oil change with the delvac. I do the top-side oil change...and only got about .75 gallons of oil out. I usually get about a half quart more from my changes...but this time it seemed pretty low. I checked my dip stick before putting anything in...and it was empty. I kept searching for more oil to pump out but it was bone dry. I filled it up with a gallon of Delvac and it looked good to me...not overfull (like I had missed a bunch of oil somewhere).

Anybody have any ideas why I am missing so much oil? Did I burn it off? Is that normal?

Did you suck the oil out of the oil filter cannister?

Delvac does seem to dissapear in some cars. Especially (I think) when you switch from something else to Delvac. I've experienced this personally and on a few other's TDIs. Not too sure where it goes though, I think it's slightly more volatile and gets burned off.

Check the level again after it sits for awhile, I suspect you may have overfilled it. I don't think burning off 1/4 gallon is very likely.

Hmmm... .75 gallons in 10,000 miles...that's a LOT better than 36 GALLONS/10,000 miles. I had to live with that for 20,000 miles.
You try pouring almost 75 gallons of oil quart by quart...
Count your blessings.
-BB

Gee would you believe that in over 49,000 miles I really dont know what the quantity of oil to add when the dipstick hits the ADD mark??

For my full system, (top of the hash marks when following the oem owners manual oil measurement procedure) I evacuate app 4.25 qts= 1.0625 gal (to stay with your metric) with a MityVac evacuator. So by process of elimination what you say seems pretty close. (1.0625gal-.75 gal= .3125 gal or 40 oz= 1.25 qts.

Needless to say it is much easier to get a more precise measurement if you keep the oil level between the hash marks. So a gal of delvac in my experience puts it right in the middle of the hash marks to slightly more to the lower hash mark.