Fuel Additives for Diesels

ncc1701e

Well-known member
We are considering a second truck (F250 6.7L Diesel). I will readily admit that I've very limited experience with a diesel engine. A couple questions come to mind for some of you who are more knowledgeable.

1. What additives do you use in your fuel?
2. Do you use the same additive year round or something different in colder weather?
3. How cold is cold before switching to a different additive if you do swap?
4. If you happen to have a new truck with the extra tank that treats your exhaust system, what additive do you use there?
5. Have you actually seen any performance improvements with these additivies as advertised?
6. Any advice on general things to keep in mind about maintenance differences?

Thanks guys.
 

codycarver

Founding Wyoming Chapter Leader-retired
1. Stanadyne, although Ford has one also
2. Same all year
4. Urea or "Diesel exhaust fluid". I bought 2.5 gallons when we purchased our new truck but have not needed to fill between regular service (I've only had two though)
5. Don't know. I have used Stanadyne in all my diesels since the ultra low carbon fuel was mandated.
6. I have my trucks serviced every 5,000 miles.
 

JohnDar

Prolifically Gabby Member
I was using DieselKleen in mine, both the summer and winter mixes, until I got six large cans of DieselMate for free. When it runs out, I'll go back to the DieselKleen. Why DieselKleen? Because it's available at any WalMarts. With the different mixes of DieselKleen, I usually switched when the temps got below 32 deg. for a while. The truck sits out on the driveway all year, and I've never had a problem with fuel gelling or cold starting in the winter.
 

cookie

Administrator
Staff member
HERE is some interesting reading regarding additives.
It should help understand how and what they do as well as giving you performance stats of a bunch of products.

Peace
Dave
 

Bob&Patty

Founders of SoCal Chapter
Well Dave, looks to me like B5 Soy is the best. But I would have to move to ND to use it. I have used it when there and OL' smokey did seem to run better. Exhaust smelled like popcorn.
 

GaryTawny

Member
We just purchased a new Silverado 2500 HD diesel Duramax and I asked my mechanic the same question about additives as this is our first diesel engine. He also recommended the Diesel Kleen products that an earlier poster (John) did. I researched it and that is what we have decided to go with as well. Our mechanic has the top rating in Central Texas and I trust him but glad to see John share his experience with the product as well. Good luck to you. We love the truck and capabilities it provides.

Gary
 

PUG

Pug
I have used a few different kinds and currently use one that I picked for best lubricity etc. etc. from web searching and comparing. It was quite expensive and does it help danged if I know. Doesn't sound any different, doesn't run any different. etc. I bought a gallon of it and use it when pulling heavy on my
Cummins. There is a web site comparison of all the different ones out there that I used to pick one.
 

Delaine and Lindy

Well-known member
I don't think any additives are need except in extreme cold weather and then only a additive that prevents Diesel from Jelling. Happy Trails....
 

lwmcguir

Well-known member
I don't think any additives are need except in extreme cold weather and then only a additive that prevents Diesel from Jelling. Happy Trails....

Not sure how many million miles we have run the various diesels but all without any additives unless we were operating at 10F below or worse. We blend or buy blended fuel (Kerosene or #1 used to blend) to get us to -10, after that we only add additivies as needed, but try to avoid operating anything more that one tractor / truck in that kind of weather.

We do use Cenex fuel here or Caseys on the road. ( Casey blends from Nov/March ) Some outlets blend fuel and others dont. If they dont and you are going to travel in cold weather then you have to add a Cetane booster. On the ranch if we get caught via an early cold snap we use 1 gallon of unleaded to 50 gallon of #2 diesel. This isnst recommended for the latest engines but works fine on all of the older ones. Dont know about Chev/Dodge but all the newer Fords have fuel heaters so the gelling isn't the concern it was years ago. You do have to maintain a minimimum tank level for some of the systems to work. You can Gell up the 7.3 style heater which is below the filters however. Found that out in a very cold blizzard that came few a number of years ago when I got cought out without winterized fuel in the tank.

If you are traveling on the hiway in extremey cold temperatues it is worthwhile to use an addivtive as noted above.
 

RoadJunkie

Well-known member
I've been using Opti-Lube for most of the 18K miles on my truck. I bought the large economy size and just keep a smaller plastic bottle in the bed of the truck to squirt some in during fill-ups. Has it helped? I dunno...but doesn't seem to hurt. I'm not going to claim that using an additive is pegging my MPG meter, it's hard to consistently measure improvements in MPG when even a 10% difference is so small! I have the 6.4l Power stroke and use the same additive year round.
 

mmomega

AnyTimer
a 2nd with what JohnDar mentioned. I've been using DieselKleen as well. I just dump a few ounces in at fill ups and keep on going down the road. Xtra fuel lubrication never hurt anyone so why not right ? Been using it throughout summer and not that it's starting to get cooler.
 

porthole

Retired
We are considering a second truck (F250 6.7L Diesel). I will readily admit that I've very limited experience with a diesel engine. A couple questions come to mind for some of you who are more knowledgeable.

1. What additives do you use in your fuel?
2. Do you use the same additive year round or something different in colder weather?
3. How cold is cold before switching to a different additive if you do swap?
4. If you happen to have a new truck with the extra tank that treats your exhaust system, what additive do you use there?
5. Have you actually seen any performance improvements with these additivies as advertised?
6. Any advice on general things to keep in mind about maintenance differences?

Thanks guys.

1. DiesleKleen, but when my current supply is gone I will be ordering the motorcraft brand additive.
2. When the temps get below 20 I change to the winter version of Diesel Kleen
3.
4. No additives, only DEF - diesel exhaust fluid. Have to be very careful about contaminating either the DEF or fuel tank on the new trucks.
5. None - 0 - nada - zilch etc
6. If you are going to do it yourself, Dieselfiltersonline.com is a good place to get supplies. Free shipping if you order over $250.00
 

pegmikef

Well-known member
Do these additives do anything to preserve the fuel like the stabil products for gas. I am replacing my gas tank with a transfer flow fifty gallon tank and I can see the fuel sitting in the tank longer when I am not actually traveling. I know with my gas powered stuff (e.g., boat, expedition) if I'm not careful I will get a varnishing effect unless I treat the gas or run the engine frequently. Is the same thing true for diesels?
 

Nabo

Southeast Region Director-Retired
We have never used any additives to the 2005 or 2009 diesel trucks we've owned and haven't had any engine problems. Even checked with the dealership and the manual which didn't state anything about additives.
 

Geodude

Well-known member
One thing that hasn't been mentioned is to get under the truck once per month and drain the water separator. Ford now recommends this in the latest version of the 6.7 manual. I have it scheduled in our on-line calendar as a monthly task. I collect a few ounces in a glass jar and look for water in the mix. So far, I've never seen any.
 

traveler44

Well-known member
In have used the Dieselkleen but if it gets really cold you are supposed to use the 911 version to keep the fuel from freezing up. I have worried for a long time that I don't drive out enough fuel when we are around home. Then somebody suggested that I only buy a quarter tank at a time until I get ready to travel and then fill it up. This made so much sense to me because I was worried about microbes forming from not running out the old fuel. They say the best thing you can do for a diesel is to drive them all of the time. I run the lighter oil in the winter so it gets up in the engine quicker and use a engine heater if it gets real cold.
 

lwmcguir

Well-known member
One thing that hasn't been mentioned is to get under the truck once per month and drain the water separator. Ford now recommends this in the latest version of the 6.7 manual. I have it scheduled in our on-line calendar as a monthly task. I collect a few ounces in a glass jar and look for water in the mix. So far, I've never seen any.

We have always done this with all the Diesels we have and in the past as well. If you have your Truck serviced at Ford they drain the separator as part of the service. Most reputable oil change shops do as well. Great point and if you got a bad tank of fuel this could be critical anytime and especially when it is cold.
 

porthole

Retired
At least with the new 11 and up Fords, even a slightly contaminated fuel will lead you down the path of sorrow and dismay.
 

Rrloren

Well-known member
We don't see really cold temps in So. Jersey but , at least for Dodge my understanding is they do not recommend any fuel additives. Winter fuel has anti-gelling added and I haven't experienced any problems whatsoever by not using additives in my '07 . Why spend the money when it's not necessary. My 2 cents.
 

lwmcguir

Well-known member
We don't see really cold temps in So. Jersey but , at least for Dodge my understanding is they do not recommend any fuel additives. Winter fuel has anti-gelling added and I haven't experienced any problems whatsoever by not using additives in my '07 . Why spend the money when it's not necessary. My 2 cents.

In this area you have to watch the fuel. Many of the Stations/outlets don't provide winterized fuel. They all put deicer in the fuel as well as gasoline. Winter fuel is a blend of Kerosene and #2 Diesel. If it don't stay winter blend at the pump then you are getting #2 with can start gelling around 10-15 F depending on the cloud point when the fuel was blended and delivered to the terminal. Our local coops charge 20 cents more per gallon for#1 which is what you need in the zero and below operating range. Again the new trucks have heaters to minimize the parafin issues.
 
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