DEF, is there really any difference in quality?

[Splashes3]

My 2017 3500 Sierra Dually has a 7 Gal DEF tank. I keep a spreadsheet and calculate my MPG for DEF usage. I use my truck to haul my signature 5ver and then to sight see....otherwise, it sits in my garage.

I'm getting about 440 miles per gallon of DEF for my situation.

I try to drive my truck just a little during the winter, just to use some of the DEF that sits in the tank. I do worry when it sits for long periods of time.

[RMWSierra]

Originally Posted by Chazman

I'm curious.. My new (to me) 2018 Sierra supposedly has about a 5 gal DEF tank. We bought the truck in March of this year, I have put about 4k miles on it, and my indicator still says "DEF fluid level ok". Do some diesels use that much more DEF fluid than others? I too have wondered about the quality of different brands as I'm guessing I will need some soon.

My Ram DEF level gauge doesn't start indicating off full until first 1/4-1/3 is used. Bad design

[B and B]

Originally Posted by milkman55

I use the Blue DEF box because I don’t go to truck stops. I can go 800 miles on a 2.5 gal box and I add one box every other day of traveling. I just got 2 boxes for $24 at Tractor Supply on sale. I am sure I could save money, but my convenience is more important to me.

That usage seems high to me.

[Splashes3]

I forgot to mention, I use the Walmart DEF for the most part....unless they are out.

[Walholler]

Chazman, I own a 2015 Chevrolet 2500HD that has a 5 1/2 gal. DEF tank. If not towing I get a 1000 miles per gallon of DEF, if towing our 5th wheel camper then the miles are much less. Your OK light or indicator will not come on until you get down to around one gallon remaining. On my Chevy, it will tell me how many miles I have remaining until the truck goes into the limp mode.

[D W]

I myself don't use DEF, but the Walmart brand (SUPERTECH), seems to be a hot seller. At any given time, you can go to any of the 3 Walmarts in Anchorage and find trash cans as well as shopping carts full of the empty containers in the parking lots. I've also witnessed the same at the Walmarts in Wasilla and Fairbanks. Must be OK stuff.

[Chazman]

Originally Posted by Walholler

Chazman, I own a 2015 Chevrolet 2500HD that has a 5 1/2 gal. DEF tank. If not towing I get a 1000 miles per gallon of DEF, if towing our 5th wheel camper then the miles are much less. Your OK light or indicator will not come on until you get down to around one gallon remaining. On my Chevy, it will tell me how many miles I have remaining until the truck goes into the limp mode.

Good to know, thanks for the info! BTW, I'm amazed at the highway mileage I get with this truck. Heading back to RI from NH I was getting 27 mpg doing 65 - 70.

[Jcrow9]

Originally Posted by TrailWayz

Curious, how do you prevent from overfilling the DEF at truck stops?

The DEF nozzle kicks off just like the fuel nozzle.

[ThruHiker]

Originally Posted by Walholler

Chazman, I own a 2015 Chevrolet 2500HD that has a 5 1/2 gal. DEF tank. If not towing I get a 1000 miles per gallon of DEF, if towing our 5th wheel camper then the miles are much less. Your OK light or indicator will not come on until you get down to around one gallon remaining. On my Chevy, it will tell me how many miles I have remaining until the truck goes into the limp mode.

This. When not towing, the gauge never seems to change. Towing, it does. I’ve been using the cheap Walmart Supertech DEF since we bought the truck, without problem. The one time, towing, where low DEF and low diesel coincided, I pulled up to the truck pumps at a Love’s I think it was. Went in to get the diesel turned on and said I needed DEF too. The girl said, “Oh, we just had those put in, they’re not turning them on until next week sometime.” 😦 So, I wound up buying 2-1/2 gal of whatever they had there in the store for $16 or something outrageous like that. Diesel price was great though! 😄

[5er_tom]

I read somewhere that DEF shelf life is 2 years.

[5er_tom]

Just purchased two 2.5 gallon jugs of Blue, for $9.99 each at Fred Meyer gas station.
Got it at the pump island. Did not have to get out of the truck. Here in Oregon they only have full service. The attendant put the 2 DEF’s in the truck bed while filling the diesel truck. Can’t get easier than that.

[Chazman]

Originally Posted by ThruHiker

This. When not towing, the gauge never seems to change. Towing, it does. I’ve been using the cheap Walmart Supertech DEF since we bought the truck, without problem. The one time, towing, where low DEF and low diesel coincided, I pulled up to the truck pumps at a Love’s I think it was. Went in to get the diesel turned on and said I needed DEF too. The girl said, “Oh, we just had those put in, they’re not turning them on until next week sometime.” 😦 So, I wound up buying 2-1/2 gal of whatever they had there in the store for $16 or something outrageous like that. Diesel price was great though! 😄

Thanks, this is more good info for me. I didn't mean to hijack the thread, but this is my first diesel and I'm still learning.

[eaglecrest]

I've been told that Ford and Ram are the best DEF - that's independent service people advise. I get Ford DEF at my local Ford dealer for $24.75 that's 5 gallons(comes in a case of 2 2.5 gal containers). My son uses Blue DEF and he just spent $3400 on getting his system fixed and they told him to use either Ford or RAM DEF. I'm not saying one is better than the others - just what service people told me.

[MoJoe1003]

Originally Posted by dwilli1

Hey TRN, will the truckstop pump nozzles fit a GMC 2500? Or do they have smaller nozzles at a pump alongside them? I always thought those nozzles are too large for standard pickups. I've only had my pu a month, filled DEF from BlueDEF 2.5 gal box.

DEF nozzles are all the same. They will fit in your GMC 2500. Diesel fuel nozzles are usually bigger than gasoline nozzles. However, that is not always the case. Had a friend who was riding with me on an 1800 mile motorcycle trip manage to fill his Harley with diesel fuel! It was an Amoco station and their diesel pumps had yellow handle covers instead of green and the nozzle fit his tank. Not one of our better travel days!

[The Evil Twin]

I think I said this in another DEF thread- its just water and cat urine, not rocket surgery. As long as it meets the requirements set forth by ISO for purity, burn it. I have shy of 55k and my neighbor is approaching 200k on $8/ 2.5 gallon jugs from Tractor Supply and Southern States. Not one emission related repair.
I do get it at the pumps when travelling just because it is right there at the tractor trailer pumps. A bonus is both the fuel and the DEF is cheaper there. Too easy not to top it up there.

[FOURWHL]

This is starting to feel like a tire pressure thread

[Vince and Charlette]

Here's the site from Sinopec who makes DEF: https://buysinopec.com/blogs/news/ho...ust-fluid-last. They, along with two other sites I checked, say max shelf life is two years depending on temperature and a few other things. DEF freezes at approximately 12 degrees F, but manufacturers have done things that lower the freezing temp. (See package for details.) Personally, although we always fill up at truck stops, I don't keep my backup emergency jug much longer than a year.

[The Evil Twin]

Originally Posted by FOURWHL

This is starting to feel like a tire pressure thread

[PhoneDude 8289]

Peak Blue has a new one out "Peak Blue platinum" at almost twice the price. I don't see anything special about it, just two ingredients, urea and water.

[IchLiebeBier]

Shelf life in a store is much longer than when you put it in your tank, depending on temperature, of course.

I personally only fill it up half-way, since I don't currently tow enough to use it up very quickly. I've read that it will go bad more quickly than I'd use it if I fill it up.

Also, since the DEF tank itself isn't heated overnight, I like to give it expansion room in case of a hard freeze. Something to think about.