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Cheapest DEF

4K views 24 replies 11 participants last post by  RAINEY  
#1 ·
NAPA has the cheapest DEF I have found, even cheaper than walmart.

4.39 a gallon.

NAPA AUTO PARTS
 
#5 ·
So I am at 6100 miles and I haven't towed and the warning to fill it up came up. I don't know if Ford didn't fill it up all the way or what, but I have 400 miles till empty on it so instead of changing it at 7500 or 10K when I do my oil, I now have to do it at 6K. I need roughly 5 gallons to fill it up all the way which will reset the alert. From Walmart $22 plus tax every 6K is expensive over the life of the truck. So yes, I am trying to find it at the cheapest place I can.
 
#6 ·
There is the "Law of Diminishing Returns" at work here. If you have to fill the DEF tank every 6100 miles (I have not seen that to be the case but) then in 150,000, you will fill it 25 times. Since it's a 5 gal tank, you will probably never want to put 5 gals back in it (much like your fuel tank) but for the sake of discussion, let's assume 5 gals.

That means you will use 125 gals every 150,000 miles so for every $1 difference in the cost per gallon, that's $125 spent or saved. I suppose it depends upon how many miles you drive a year and how long it takes you to put 150,000 miles on the truck, but $125 delta operating costs on a $65,000 truck seems to be a "nit" compared to the cost of Fuel, Oil, Tires, Maintenance Labor, etc.

Assuming you get 18 mpg, you will use 8,333 gals of fuel driving 150,000. Better to save the fuel cost by not having to hunt the cheapest DEF since that works out to requiring 1 1/2 cents savings on fuel cost during the same period.

Makes you really consider what is important when you look at all the inputs and outputs.

BTW - Pilot, Loves, and several other Truck Stops in the Houston/ Austin area sell bulk DEF.
 
#7 ·
all valid points. Since I drive to Houston from SA and vice versa, there is a loves on my way right off I-10 so driving around to find a cheap price is not really an issue there (if they have bulk DEF of course). I agree that driving around looking for cheap DEF, gas, diesel, etc. is a lost cause and you are basically spending a dollar to save a dime.

Also, there is a NAPA near me so I am not really going out of my way to pick up the cheaper DEF.

I was posting this for people who were looking for cheap DEF instead of spending more than they have to.

I am going to fill my DEF up to the brim and see how long it lasts. I hope it was just not filled up all the way...
 
#8 ·
The first time I filled mine, I just used a single 2.5 gal container and then risked it out (including the spout, etc.) very well and now use fill it when I happen to be at a Pilot, etc. That way you get the best price on the DEF and always have some "on hand".

I check mine every so often to make sure I'm above the 50% level and when I get that alarm, then I drop in the 2.5 gal I have on hand. I usually only have to fill it every 7,000 to 9,000 miles. More if city driving, less if Highway/Towing.

Safe travels, D
 
#10 ·
Contaminated DEF is a $800 repair bill at the dealership if it takes out the pump...
 
#11 ·
Are you saying that there is a greater degree of risk buying it out of the pump (bulk) at a truck stop? I know when I stopped buy I had to wait for a big rig to fill up. I would think that it would be pretty costly for the truck stop if they were found to have caused damage to a few of the Semi Tractors since quite a few of them use it now.

John
 
#21 ·
No. The shelf life is mostly guidelines for warehousing so distributors don't sell you bad DEF. It is also not a good idea to stock pile it because you found a good deal and store it in a hot garage or barn. Your constantly using your DEF in the truck reservoir and topping off with fresh.

Jason