gkgeiger

Has anyone gone to a truck stop and used the DEF pump. I had a diesel MH and at Flying J it is about $2.80 a gallon. You can also fill it and not have to guess how much is left in the tank. I just don't know if the nozzle will fit. Please, no speculation just someone with experience. Thanks,

350MH83

I have always refilled at truck stops. I never bought a single bottle of DEF. The nozzle fit but some of them will require a small adapter to be fitted to the nozzle first. The guy at the truck stop always had that handy when it was needed. I usually refilled every 5000km or so, and never managed to put more than 5 liters at once.

gkgeiger

Thanks, that's the kind of info I'm looking for.

fabbrisd1

On a ML250 - there is no real advantage of "topping off" - so you know when the tank hits the initial "low DEF" after 8K-11K miles depending on drive style - your reserve at that point is good for about 1200-2000 miles - however. if you go too far after that - the 2nd level warning - "Low DEF 9 Starts Left" - you need to take care of it right away because once you run out of starts - you engine will be "locked" and will need to be towed to the dealer for system unlock

Pump DEF is fine - so are the 2.5 gal retail-auto-parts-store DEF boxes for $15 or under - if you use the "box" - throw away whatever is left - no need to risk contamination etc over small dollars..