BlueTec, First DEF Refill
I decided that no way would I pay a dealer $275, or whatever they charge, for a DEF refill; I would do it myself.
There is no dashboard gauge for DEF like there is for fuel, so you have to make a guess about the level. You can wait for the DEF level to get very low and the car will then warn you that you have 16 starts left until it will NOT start. I had read that 7 gallons of DEF is good for 11,000 miles or so.
My new 2012 ML has 6234 miles on it so I figure that the DEF tank must be about half empty, some would figure that it is about half full. Time to add DEF, it will probably take 3.5 gallons or more.
$15.00 for a 2.5 gal plastic container full of DEF, with a flexible plastic pouring spout/hose from Autozone. Simple task, attach the hose, insert one end into the vehicle's DEF tank and pour. The hose cap is a cheaply made device without a gasket but it does have a little rubber vent hose for air to enter as you pour out the fluid. When you start pouring it into the tank, it leaks from where this pouring spout/hose meets the container... makes a big puddle on the ground and gets all over your hands. Then you observe that the plastic container is compressing as the fluid runs out... that little vent hose isn't working so the flow of fluid slows to a dribble. You withdraw the hose from the vehicle to allow more air into the container. You do this several times and finally it looks like the container is nearly empty when DEF starts gushing out of the vehicle filler tube. The tank is full. I would guess that I put in 2.1 gallons before it over flowed (running down the side of my car, and all over the tire, wheel, brake calipers, etc.). 2.1 gal./6234 miles; my estimate of the usage was way off.
The next time, I will wait until the vehicle tells me it is getting low. I will also ensure that the cap is fully seated and not leaking.
Some people here have mentioned getting a proper 1 Qt. jug from MB to make the filling process cleaner. You then have to refill the 1 Qt. jug (from the 2.5 gal container) 10 times and that sounds kind of awkward.
In any case, it ain't a big deal. Beats spending $275. And... more than you wanted to know.
4 gallons per 10k miles is no big deal...luckily no mess.



