I refilled the DEF using a fuel type pump So as we know, the M-B dealers tend to get about $150 to fill the Diesel Emission Fluid reservoir in our Bluetec diesels. DEF is DEF, in fact the same bottle that is sold at M-B dealers also has VW and Audi and BMW part numbers on it.

My M-B dealer sells a 1/2 gallon (2 liter) bottle for about $10, and the tank holds somewhere between 6 and 7 gallons. In fact, my dealer quoted me $10 a bottle for however many bottles it would take to fill (even though they fill from a big 55 gallon or so drum of DEF.) FYI the 7 gallons or so of DEF that the car holds lasts well more than the 10,000 miles recommended between oil changes and services.

So, I'd read that many truck stops today have a DEF pump right next to the diesel pumps for the big 18 wheel trucks. I googled and found such a truck stop about half an hour from my house. But the car's tank has a proprietary cap and you can't just stick a nozzle in there and fill it up. One person recommended buying one 1/2 gallon bottle and then cutting off the bottom, and using it as a funnel. Sounded good, so I did that....



And I learned a few things:

1. This is a two person job. You have to push down on the bottle to get it to drop the fluid into the tank, but if you push too hard and the fluid goes in too fast, then some fluid shoots up the small tube which is meant to let the air escape out of the tank while the fluid goes in. There is a delicate balance to how hard to push, otherwise you are making a huge mess.

2. The truck stop pumps don't work like gas stations that you and I are used to. You have to go inside and they activate the pump from there, and they'll look at you funny because you're not dressed like a truck driver, and your truck doesn't have a truck number. You can't just drive up and swipe your Amex card.

3. It took me a long time to pump five gallons into my car, like 20 minutes. Any faster and the DEF shoots out the exhaust tube in the bottle.

4. The only way that you know that the tank is full is when the funnel won't allow any more DEF into the tank. So you then have to unscrew the funnel, and discard the little bit that's left inside it.

5. Now the good news: My 5.061 gallons of DEF cost me $14.67 or $2.899/gallon. So I filled the tank for $15 instead of over $100.

Overall, I saved about $100. Was it worth the hassle? I'll let you decide that. For me, I am not really sure what I'll do at the end of the next 10,000 miles.

 

Well done ,sounds a sensible idea. Just wondered why you cannot fill a 20 gallon drum with a wide neck then decant to your car at your leasure?

 

I think I would go to Walmart and buy a couple of 5 Gal plastic gasoline containers and fill them at the truck stop and then fill the vehicle once you get home. They are a little less the $10 and have a pour spout for use in dispensing fuel into a car or truck.

Have you tried to see if the truck stops sell the stuff in bottles. I am sure you can get it much cheaper than what MBUSA wants you to pay.

 

Neat idea, but much quicker with a long neck narrow funnel and a couple 2.5 gal jugs of AdBlue/DEF from VW or a truck stop. Second person helps to elevate the funnel slightly to give air vent and ensure no spillage. And just in case, usually wrap a towel around the filler neck to head off any potential spillage (you don't want this stuff touching any electrical connections on the tank)

 

I think this is the best idea. If you're refilling at 10k intervals, a single 5 gallon can will typically do it. DEF does have a shelf life so you don't really want extra.