Def fluid

[SDM]

Have a 2011 Duramax. Have had a sensor problem. Dealer says the def from Walmart is giving some problems. Any thoughts.

[magicbus]

I haven't had to fill my Sprinter yet. How much does it hold and in what sizes is it sold?

Thanks,
Dave

[tagretired]

I stopped buying the Peak brand, even at Walmart. Figuring the $/gallon price, it is cheaper just to buy it at the truck stop at the same time I am re-fueling. My Mercedes Sprinter has a builtin gauge in the instrument panel that allows me to see the DEF level (plus there is a dash light that comes on warning the DEF is getting low). I know that I need to top off the DEF when I've gone around 6,000 miles. I usually stop at Pilot/Flying J or Love's for fuel. The DEF is way cheaper, there, and can count on it being fresh, plus i don't have to find a place to store the box in one of the basement compartments, if I don't use the whole box.

[Lynnmor]

A product labeled DEF must meet the standards set by law. All brands are the same, buy by price and age of product.

Amazon really doesn’t have free shipping, the price of heavier products is higher to pay that shipping.

[ktmrfs]

Only True Mosnowman wrote:
I just ordered Motorcraft DEF off of Amazon. My 2018 Ford F350 manual specifies I use Motorcraft brand. This is my first diesel, so like many other newbies I am apprehensive, most likely for no good reason. Is Motorcraft a good brand? Thoughts?

Ford is 99.999% likely to just have a major DEF mfg put a Ford Label on a jug.

Now, if the price is comparable to others, no big deal. But if it is Like GM, the GM DEF fluid is more expensive than any major brand.

And as long as it meets the Ford spec, which happens to be a common spec for ALL DEF fluid, your ok.

If your comfortable buying the ford fluid, nothing wrong doing that. But it isn't any requirement or going to give you anything better than any of the other major DEF brands.

And as for cost, DEF fluid is one thing I've found is noticeably more expensive from Amazon than at NAPA or any major parts store or gas station. Even with free prime shipping.

[Wild_Card]

Only True Mosnowman wrote:
I just ordered Motorcraft DEF off of Amazon. My 2018 Ford F350 manual specifies I use Motorcraft brand. This is my first diesel, so like many other newbies I am apprehensive, most likely for no good reason. Is Motorcraft a good brand? Thoughts?

Your wasting your money. They cant specify the brand they can only specify the chemical properties. DEF is Urea fluid...be it Ford, Mopar, Peak or Wal Mart brands.

Ask Ford to show you there DEF mfg facility...

[Only_True_Mosno]

I just ordered Motorcraft DEF off of Amazon. My 2018 Ford F350 manual specifies I use Motorcraft brand. This is my first diesel, so like many other newbies I am apprehensive, most likely for no good reason. Is Motorcraft a good brand? Thoughts?

[jplante4]

Thanx for correcting that Bill. I forgot that NOX was the issue, not particulates.

Thankfully with a 23 year old CAT, I don't need to deal with any of that.

[ktmrfs]

jplante4 wrote:
DEF is different from DPF. With the particulate filters (2008 thru about 2010), they increased the exhaust gas recirc and filtered out whatever didn't get re-burned.

DEF uses a catalytic filter and the DEF fluid to wash the particulates out. The EGR rate was reduced.

People who know and people who have owned coaches with both technologies say that DEF is a great improvement. At any rate, if you look at a graph of gas vs. DP class As, the turning point was when the government got involved.

well, not really correct:
DEF and DPF are used to reduce emissions, and each performs a different function, true.

DEF is used to reduce NOX, not really any direct effect on particulates. urea combined with NOX to yield N2 and water. doesn't really do anything for soot. but it does reduce the need for EGR which is and has been and is used to reduce NOX emissions.

And EGR isn't real good for performance or economy, and is problematic in operation as well. Navistar tried using EGR only to control NOX emission in class 8 engines. pretty much bankrupt them, and ran into troubles with EPA. Never could get it to work well enough.

I'd rather have urea injection for NOX emissions and limited EGR and deal with urea injection issues if they arrise.

DPF uses a turbine flow to trap soot. like the old oil bath air filters. then once the filter gets to a certain soot level, extra fuel is introduced and burned, to increase the temp in the DPF to burn off the soot. In the current duramax there is a 9th injector in the exhaust header to inject fuel into the exhaust stream and raise the exhaust temp high enough to burn off the soot, basically carbon from the DPF.

DEF is constantly being injected into the exhaust stream, roughly 1 gallon of DEF for every 100 gallons of diesel fuel.

Since the DPF and DEF and cat converter are used to meet emissions, both systems should be covered for 100K miles or something like 8 or 10 years under the emissions warranty.

urea (DEF) is used extensively in many power plants to reduce NOX power plant emissions. Both in Coal fired and Natural gas fired power plants.

[jplante4]

DEF is different from DPF. With the particulate filters (2008 thru about 2010), they increased the exhaust gas recirc and filtered out whatever didn't get re-burned.

DEF uses a catalytic filter and the DEF fluid to wash the particulates out. The EGR rate was reduced.

People who know and people who have owned coaches with both technologies say that DEF is a great improvement. At any rate, if you look at a graph of gas vs. DP class As, the turning point was when the government got involved.

[joe_puma]

Its a **** system, destined to failure. Another sad thing is I almost had to have my diesel particulate filters replaced, bad sensor in the filter they couldn't get out. One guy had an idea so I left it till the next day. They were able to drill it out and re tap the hole. Thats when he informed me the "filter" wouldn't be covered under GMPP. It was like 2 grand to replace. I only had 60K when I started having all the sensor and heater issues. Also heard the EGR gases will eventually running the turbo!

[esfd243]

I have had sensors, DEF tank and heater/pump replaced, all on DEF Blue from NAPA. I switched to WM brand 15,000 miles ago an no issues. 105,000 on my 2012 Duramax I bought new.

[allen8106]

SDM wrote:
Have a 2011 Duramax. Have had a sensor problem. Dealer says the def from Walmart is giving some problems. Any thoughts.

I have a 2013 Duramax I bought new and have used DEF from all over the place including, mostly Walmart, without issue.

I had an issue with the sensor and the dealer replaced it. seems there was a recall.

[ktmrfs]

Wild Card wrote:
They make a DEF refractometer. You can buy one at most auto stores. Take your own sample then you'll know.

AND check experation date. I check date code and use the refractometer on every jug I buy. So far have used the peak Blue DEF, but all are the same.

One way to have it go bad is to have the jug stored at high temps, like over 100F continously. then shelf life degrades.

[prfssr]

Rancher Will wrote:
I own a small trucking company, two cattle ranches and I pull our Montana 5thWheel with a diesel RAM truck. On average I pay for over 150 gallons of DEF per week. I learned that I save over $2.00 per 2-1/2 gallon jug by my employees buying at WalMart rather than at truck stops and other sources. We have had no problem with WalMart DEF in the Blue jugs plus it is cheaper than even bulk supply.

So, I guess it depends on where you live but I am in Kentucky and it is definitely cheaper to buy at a truck stop at the pump.
Truck stop at the pump = $2.679 per gallon
DEF at Walmart = $10.98 + .66 tax = $11.64 divided by 2.5 gallons = $4.65 a gallon.

I am unsure how buying the box is cost effective.

Mark