New to Diesel ....

[John Millner]

Ok, lots of good comments and advice. I have a 2010 Interstate, I'm not a mechanic and don't carry an extra filter but I try to be careful where I buy my fuel. Mercedes tells me to stay away from biofuel unless it's 5% or less I think. If it's Shell diesel it's usually good but I've stopped at Shell stations and when I attempt to put in diesel the pump says "not a shell product".
Second and a very important issue with a diesel Interstate is the size of the fuel nozzle that you must find. Many truck stops have the larger fuel nozzle that will not fit the Interstate yet they usually have at least one that does. So when traveling look for the auto diesel usually where regular cars are, and have a green pump handle that says DIESEL. Always ask yourself every time that if you put in the correct size diesel nossle with diesel fuel. I can't tell you how many times when I stopped at the truck stops I had the wrong size fuel nozzle. Not anymore.
I love the Interatate and the mileage diesel delivers.
I hope my advice saves you time and trouble.

[Tod3]

Diesels need clean air and clean fuel. The clean fuel point has been covered by several good posts. I also suggest you pay attention to the engine air filters and change them at recommended intervals. This is even more critical than with a gasoline engine, since a diesel fires off compression (no spark plug) and needs a clean air and fuel mixture to run at its best.

Also, if you will be driving in very cold weather, you will need to add cetane boosters to keep wax from precipitating out of the fuel and blocking the fuel flow. There are a number of fuel additives on the market, readily available at truck stops, that act as both cetane boosters and injector cleaners. I add them to my fuel all the time, but that is mainly so I won't forget when the weather turns nippy.

Related point: refineries run "summer blends" and "winter blends". The summer blends are even leaner and drier than the winters. This can also make a difference for extreme cold, so if you have not run your rig for a while and the weather has turned cold, you may want to top up with some fresh fuel.

I wish you safe and happy travels!

[guskmg]

i think most late model diesels have enough pre-heating of the fuel that additives for waxing are not necessary to winterize diesel fuel. Most truck stops carry winterized fuel when the weather starts to get cold. Last November, I went from Denver to Fort Worth to Jackson Center with temperatures as low as 8 degrees F and my GMC Duramax started every morning for over three weeks. Be sure and ask if the fuel is winterized if it is not posted.

[73shark]

Originally Posted by Brucet45410

So by adding 2 Gal of DEF, I've bought myself 2000 miles until the next DEF low light? 1000 miles/DEF Gallon?


2014 Airstream Interstate
Currently a "Weekender" but planning a cross country trip next summer.

Didn't proofread. I meant it holds five gallons. Sam's carries DEF in handy 2.5 gallon containers with a nice pour spot.

[GCinSC2]

Even if you can't or don't want to mess around changing a fuel filter, carry one with you. Then when help is available you're not stuck for a day while your oddball (to them) engine fuel filter is found or delivered. And it can prevent you from having an unknown off brand filter being used.

[Titus]

I have added 2.5 gallons of DEF a couple of times, and it quicky fills to the top of the tube, even when adding slowly from a jug. Then 10 minutes later it will drain down and I can add another 0.5 gallons before it fills again. Seems to be a tube that (presumably) goes from the DEF tank and goes to the fill tube - as a tank vent. Vent tube seems to be clear. Anybody else have similar problems?

[Tater]

I've added DEF to my silverado twice but it takes the full 2.5 gal with no problem. I also wash off the DEF crystals from the pour area if any are visible.

[Protagonist]

Originally Posted by Tater

I've added DEF to my silverado twice but it takes the full 2.5 gal with no problem. I also wash off the DEF crystals from the pour area if any are visible.

DEF crystals? It only crystallizes if left to dry.

DEF is corrosive and can eat away at paint, so all of us who add our own should wash off any spills just as soon as the fill spout is capped off. Don't wait for it to crystallize.

[Tater]

That's correct, after you put it in and it dries, it leaves crystals that should be rinsed away. Water to rinse is not always readily available at fueling locations or roadside stops. In the driveway at home yes, on the road, you may have to wait until you can get to a water hose or other water source.

[Protagonist]

Originally Posted by Tater

That's correct, after you put it in and it dries, it leaves crystals that should be rinsed away. Water to rinse is not always readily available at fueling locations or roadside stops. In the driveway at home yes, on the road, you may have to wait until you can get to a water hose or other water source.

One reason why in my Airstream Interstate I extended my external shower hose to 12 feet in length and replaced the shower head with a spray nozzle. As long as I have water in my fresh tank, I can wash off any spilled DEF right away.

Of course if you're using DEF in a tow vehicle or a daily driver rather than an Interstate, you don't have that option.

[tjdonahoe]

I buy lots of fuel for my big truck and the pickup , we go coast to coast and I haven't bought any bad fuel in over 20 years, I haven't seen any water in about that long , just buy where they sell a lot of fuel or gasoline there is no magic to it.

[Tod3]

Originally Posted by guskmg

i think most late model diesels have enough pre-heating of the fuel that additives for waxing are not necessary to winterize diesel fuel. Most truck stops carry winterized fuel when the weather starts to get cold. Last November, I went from Denver to Fort Worth to Jackson Center with temperatures as low as 8 degrees F and my GMC Duramax started every morning for over three weeks. Be sure and ask if the fuel is winterized if it is not posted.

I run a 2008 Ford F350 - maybe not a late model at this point, but the owner's manual does recommend cetane boosters for extremely cold weather. My experience with extreme cold has been that the engine will start, but may stall out at an inconvenient location. By extreme cold, though, I mean sub-zero F. The last time I had problems with stalling (which is when I started paying a lot more attention to running cetane boosters) was in 30 below F temps.

[Marks71]

I have 2800 miles on my 2015 AI. I figured I'd better add some DEF and put 1 gallon in this morning. I have no idea how much I'd used up to this point since there's no way to check level, but clearly more than 1 gallon since it took it easily (assuming it was full when I bought it new).

Shark says he gets 10K miles out of a 5 gallon tank (is it 5 or 5.5?)

But I've read that DEF is consumed at a rate of 2-3% of fuel

DEF USAGE Q & A :: NOxBLUE DEF Diesel Exhaust Fluid

So if that's true:
* I would have used about 3.9 gal already (2800 / 18 * .025) Could that be true?
* and Shark would be way off (10K / 18 * .025 = 14 gallons of DEF).

Maybe the 2-3% factor is wrong. Anybody out there have this figured out? I'm about to embark on a long trip, and don't want to trigger the "xx starts remaining" function, but adding a little DEF at a time is a real pain with the handling issues etc.

Thx for any perspective or math or whatever.

[SteveSueMac]

Here's some perspective (math gives me hives! &#128513

It will depend on how you use it. It's not a straight x miles formula. Mine (a GM product) tells me it's ok until I have 20% left. I don't always wait for that warning. Like you, I might drop a gallon in every few thousand miles just to be safe.

If you're on the highway, most truck stops have DEF at the pump and you can fill exactly to the top. It won't be very hard to find on the road. You can carry a gallon jug with you for insurance - there's a mileage countdown that leads to "crawl" mode (restricted to 5mph - not kidding!) that you definitely want to avoid.

Carrying the jug, traveling on major roads - you should be good


Oh - another suggestion - get the Gas Buddy app and/or iExit app so you can locate major diesel stations near you no matter where you are. Odds are good those stations have DEF pumps.

[Protagonist]

I buy a 2.5-gallon container of DEF at my local Walmart as soon as the "DEF Chk" message comes on the message center.

According to the Sprinter Operator's manual (page 200 of my 2011 Sprinter manual):

dEF Chk appears in message center
In addition, the yellow DEF indicator lamp lights up and a warning tone sounds.
The DEF supply has dropped below 1.5 US gal (5.5 l).
After the message appears for the first time and under normal driving conditions, the remaining DEF supply will last for approximately 1000 miles (1600 km).
After that, the 0.8 US gal (3.0 l) reserve mark is reached. A warning tone sequence sounds. The engine can then only be started another sixteen times.
Add DEF supply (page 143).
After topping up, the system check takes approximately 20 seconds. The DEF indicator lamp then goes out.

Since I add DEF as soon as the "DEF Chk" message appears, I've never even had the "countdown to breakdown" message pop up telling me I have 16 starts left.

If you can go 1000 miles on 1.5 gallons of DEF, and the countdown begins when you have 0.8 gallons left, that gives you somewhere between 400 and 500 miles grace period from the first time you get the "Listen to me" nag screen until you get the "Hey, I'm serious, you'd better listen" nag screen. That's a full tank of diesel, and I've never driven anywhere in the US that was more than 1 tankful of diesel away from the nearest Walmart where I could buy DEF.

[UKDUDE]

Originally Posted by Protagonist

I buy a 2.5-gallon container of DEF at my local Walmart as soon as the "DEF Chk" message comes on the message center

Agree. And I'd like to add that from my experience, once you have the "DEF Chk" warning come on, adding 1 gallon of DEF is not enough to reset the warning. You do need at least 2.5 gallons for the reset.

[bellastream]

Just a thought maybe you could outfit the def tank with a see level tank gauge then you would know how much def you have all the time.

[bellastream]

http://www.bestconverter.com/SeeLevel-Gauges_c_108.html

[Marks71]

Originally Posted by Protagonist

I buy a 2.5-gallon container of DEF at my local Walmart as soon as the "DEF Chk" message comes on the message center.

According to the Sprinter Operator's manual (page 200 of my 2011 Sprinter manual):Since I add DEF as soon as the "DEF Chk" message appears, I've never even had the "countdown to breakdown" message pop up telling me I have 16 starts left.

If you can go 1000 miles on 1.5 gallons of DEF, and the countdown begins when you have 0.8 gallons left, that gives you somewhere between 400 and 500 miles grace period from the first time you get the "Listen to me" nag screen until you get the "Hey, I'm serious, you'd better listen" nag screen. That's a full tank of diesel, and I've never driven anywhere in the US that was more than 1 tankful of diesel away from the nearest Walmart where I could buy DEF.

My manual is different. It says the first message "Check Diesel Exhaust Fluid" will appear when DEF has dropped below 1.5 gal. Then the icon, 3 beeps, and XX starts remaining, will be the second message, which indicates DEF has dropped below 0.8 gal, which will allow 1200 more miles to be driven.

My "paranoia" is driven by my friends' experience, in which he had to actually drive to a MB dealer to get the XX starts left warning turned off, despite continually adding DEF as he drove. But that may have been driven by faulty NOx sensors, which is another problem I've read about in here.

[73shark]

Most auto parts stores sell DEF as does Sam's and Wal-Mart. When I got the limited starts warning, I added one gallon and the message went away.hmm