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BurbMan

Islip, Long Island

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Posted: 11/25/20 07:59am Link  |  Quote  |  Print  |  Notify Moderator

The owner's manual says my truck has a 5.5 gal DEF tank. I waited until I was down to 1/4 on the gauge, just above the red zone, and added a 2.5 gal box of Blue DEF from Advance Auto. Now the gauge reads FULL to the top.

So the gauge must be set to give you a long warning zone to keep you out of limp mode. This is only my 2nd time adding DEF so just getting used to all of this.

Also interesting is that the DEF I got said "Blue DEF" but the Peak brand is gone, and so is the manufacture date. No date or code of any kind on the box or the container so no way to know how old it is. With tax it was $15 for 2.5 gals, so $6/gal. Probably last time I'm buying it at Advance.


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Groover

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Posted: 11/25/20 08:26am Link  |  Quote  |  Print  |  Notify Moderator

BurbMan wrote:

The owner's manual says my truck has a 5.5 gal DEF tank. I waited until I was down to 1/4 on the gauge, just above the red zone, and added a 2.5 gal box of Blue DEF from Advance Auto. Now the gauge reads FULL to the top.

So the gauge must be set to give you a long warning zone to keep you out of limp mode. This is only my 2nd time adding DEF so just getting used to all of this.

Also interesting is that the DEF I got said "Blue DEF" but the Peak brand is gone, and so is the manufacture date. No date or code of any kind on the box or the container so no way to know how old it is. With tax it was $15 for 2.5 gals, so $6/gal. Probably last time I'm buying it at Advance.


The Walmart house brand is about $9 and it is just a generic chemical that most people seem to think makes all brands equal.

ShinerBock

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Posted: 11/25/20 08:30am Link  |  Quote  |  Print  |  Notify Moderator

Buy from the pump at truck stops. Not only is it fresh and stored in a cool place to last longer, but is also only costs about $2 per gallon.

My dealerships sells DEF. I can tell you that most of it sits out in a hot warehouse or in a hot semi-trailer for ages before being put out in the showroom which lowers the shelf life.

Old-Biscuit

Verde Valley

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Posted: 11/25/20 08:52am Link  |  Quote  |  Print  |  Notify Moderator

DEF is an aqueous urea solution made with 32.5% urea and 67.5% deionized water.

Brand shouldn't matter


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Ron3rd

Upland, CA USA

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Posted: 11/25/20 09:02am Link  |  Quote  |  Print  |  Notify Moderator

Groover wrote:

BurbMan wrote:

The owner's manual says my truck has a 5.5 gal DEF tank. I waited until I was down to 1/4 on the gauge, just above the red zone, and added a 2.5 gal box of Blue DEF from Advance Auto. Now the gauge reads FULL to the top.

So the gauge must be set to give you a long warning zone to keep you out of limp mode. This is only my 2nd time adding DEF so just getting used to all of this.

Also interesting is that the DEF I got said "Blue DEF" but the Peak brand is gone, and so is the manufacture date. No date or code of any kind on the box or the container so no way to know how old it is. With tax it was $15 for 2.5 gals, so $6/gal. Probably last time I'm buying it at Advance.


$7.88 in my area and that's all I use. The pump Def is cheaper but not convenient in my area.

The Walmart house brand is about $9 and it is just a generic chemical that most people seem to think makes all brands equal.



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IdaD

Idaho

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Posted: 11/25/20 10:11am Link  |  Quote  |  Print  |  Notify Moderator

Blue is $10 at Costco and that's what I've been buying lately because it's the most convenient. It's only a buck a gallon more than buying it at the pump.


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Lantley

Ellicott City, Maryland

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Posted: 11/25/20 10:25am Link  |  Quote  |  Print  |  Notify Moderator

You Ram/Dodge guys are fortunate enough to have a decent place to fill your DEF and maybe even gauges!
The fill for my Chevy is under the hood and there is no gauge.
I try to fill at the pump just because its much easier than filling from the box under the hood


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BurbMan

Islip, Long Island

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Posted: 11/25/20 10:36am Link  |  Quote  |  Print  |  Notify Moderator

They have it at Costco? Thanks for the heads up on that!

Lantley how do you know if you're out of DEF without a gauge?

LIKE2BUILD

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Posted: 11/25/20 10:55am Link  |  Quote  |  Print  |  Notify Moderator

Old-Biscuit wrote:

DEF is an aqueous urea solution made with 32.5% urea and 67.5% deionized water.

Brand shouldn't matter

Brand shouldn't matter, but I have a different experience. I had always used Peak Blue DEF but a local farm store had some off-brand DEF that was $7 for a 2.5 gallon container. I used the cheap stuff to fill up prior to a long trip and about 100 miles in I got a CEL and noticed that my DEF gauge started dropping MUCH faster than usual. At an O'Reilly's I used their scanner which showed a code for "Insufficient Catalyst". I topped off my DEF tank, but the CEL came back on and the excessive use of DEF continued for the trip.

When I got home I siphoned out the entire DEF tank and refilled with Peak Blue along with clearing the code. That was 6 years ago and I've used Peak ever since and have never had that code again.

Was it cheap DEF that was made at a bad spec? Maybe. Was it just old DEF that had been stored improperly and degraded? That's probably the more likely scenario. However, I decided that my track record with name brand Peak and the problems with the one use of the cheap stuff was enough to convince me to use the name brand and not risk problems just to save a few $$.

I may be spending more for no good reason, but I don't like taking the risks.

KJ


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rhagfo

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Posted: 11/25/20 11:26am Link  |  Quote  |  Print  |  Notify Moderator

Peak Blue DEF is changing their packaging and pushing that it is very pure, less contamination, for as much as I use I will continue to use it.
I also fill at 1/2 tank, and it goes to full, yes having a gauge is nice.


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