Saw another thread on Archoil and being a new (well soon to be) new Diesel owner I am trying to determine about addditives too. I live in the northeast and Cetane at the pumps is marked "Min 40". The owners manual does not seem to spec a cetane level for the 6.7 engine. What is needed? The write up published on Fords booster says ford diesels recommend a min of 45. Is that just marketing speed sine it is not specked in the manual? Should ford's cetane booster (or another brand) be used? Will it actually improve mileage? Ok, I admit I am lost on this one....

 

I've used Ford PM 22 since owning my first 2011 Super Duty. I add a few ounces to each tank of gas. They say it improves mileage. Who knows? I can't complain about the mileage of the Super Duty anyway.
I think it's cheap insurance. Probably the most important thing to do is fill up at high volume brand name stations.

 

I've been down the road that you're on. I finally decided that it would be wise for me to use Ford's Motorcraft additive. I use the Motorcraft PM-21 for summer, and PM-22 for winter. I know that there are dozens of good additives out there that claim to make better fuel economy, better acceleration, and some will probably make your coffee taste better on you drive to work. The bottom line for me is the engine warranty. If I put an aftermarket additive in my truck and there is a major problem, I imagine that Ford will find a reason to blame that additive, real or not. If I'm using Ford's additive, there's no question about it, they recommend it.


Does it provide better mileage? Maybe slightly. I've used their additive in all three tanks of fuel on this truck. (not enough time to tell) On my last truck 2014 F250 6.7, I logged every tank of fuel and experimented with and without additive. It may have provided 1.5 mpg increase, but when its that close it could be my driving, or some other condition to cause it. If it does provide 1.5 mpg, then it probably covers its cost and is money well spent.


One word of warning with additives. I have a Buddy who uses Ford's Motorcraft additive like I do. He had some trouble with his truck shutting down and starving for fuel. It was driving him nuts. He ended up finding out that when he removed the additive bottle cap that a little white cardboard seal (about the size of a dime) in the cap that seals the cap stuck to the bottle, and not the cap. When he dumped the additive into the tank, the cardboard seal went in. It ended up in the fuel pick up cup inside the tank. It would fall to the bottom of the tank when the engine was shut down. Then when he'd be pulling hard and a lot of fuel was being drawn from the tank, the seal would get sucked up into the fuel pickup and the truck would starve for fuel and die.
This problem drove him crazy and he was really disappointed with his truck, until he found out what happened.


The moral to this story,,, check your additive bottle before dumping it into your tank to be sure that the seal is in the cap and not on the bottle.
Bob

 

My first Ford diesel (and first diesel ever, except my tractors)...I religiously added Ford PM22 to every tank fillup. Now on my 3rd diesel, sometimes I put it in, and sometimes I don't for several tanks. The pumps where I live are all rated for 40 cetane as well. I don't really see a difference.

 

Any time I've heard a spiel from Ford on their motors they seem pretty keen on pointing out the cetane number and that many pumps don't meet the standard. Considering the cost of additive vs the cost of repairs, I wouldn't want to mess around with it. In principle the concern makes sense as well. If you're ignition is taking a little bit longer to start it's likely a little bit more incomplete each time and over time that would influence the emissions stuff with fouling. My hunch is they probably don't want to make the motors require it, but it's a "cheap" way for them to make a motor that meets emissions standards, and then passes part of that cost to the consumer who now has to run a more expensive fuel. Making a motor equally clean on 40 CN might cost $X more. I could be wrong, but it's dumb enough to make a good bit of sense.

 

I run the pm22 in every other tank, like rjc2 stated I see about a 1.5 mpg difference on the highway with tanks that have the additive compared to tanks without, around town really don't see a difference except for the "clatter" being a little quieter.

 

Running a CN higher than the minimum specified by the engine manufacturer provides ZERO benefit. CN does not determine fuel quality, just how quickly ignition happens. Running a significantly higher than necessary CN number will result in ignition happening too early...which changes timing and reduces power.

Minimum CN number in the US is 40. I have seen Ford diesel engine supplements stating 45 is the recommended CN. I believe the engine runs perfectly at 40 but running at 45 is also fine and allows Ford to profit on PM22 sales.

Running too low a CN will result in harder starting, especially when it is cold. It can also create more emissions because the later combustion is not as complete.

 

I think lubricity is more important than cetane with the 6.7 no?

 

I add the additive mostly for the added antigel properties for winter. As you can tell it's a mixed bag of cats when it comes to actually how much benefit it does or does not have.

I figure for the time and cost why not add fuel addtives. If the certain is wasted as result of to much then so be it. That being said I have never heard of it effecting the timing. What I read is it is more like how they justify pee, you have to much of x vitamine, it just gets peed out.

 

From what I have read a higher cetane number allows for a more complete burn of the fuel hence less soot formation which helps keep the EGR cooler clean and contributes to less DPF regenerations. Lubricity is also important to meet the required wear scar value for the injection pump. However, no data is provided to support the claim. There is no practical way to test the fuel prior to use so there in lies the market for this stuff. Blanket statements are used about US fuel quality and the stations I have been to have no idea what they sell. There is also such a variance in manufacturer recommendations that use the same or similar high pressure injection equipment, for instance BMW does not recommend the use of any additives, even in the winter yet I am almost certain they use a Bosch CP4 injection pump.


My complaint with the Ford additives is that they are not clear in what they accomplish. The product sold for winter use that lowers the CFPP of the fuel should provide the same benefit as the summer product.

 

Diesels inject their fuel usually around 15 degrees before TDC. The air mixture at that point is already hot and compressed, but the diesel with the expected CN will not auto-ignite until TDC is reached. Now, if a very high CN fuel is used, auto-ignition will happen before TDC is reached, and the result is that some of the fuel's energy is wasted trying to turn the engine backwards. On a mechanically-timed diesel engine (older or off-road applications) there was no control at all. High CN = wasted power. On our trucks, the PCM can control injection timing...but only if the PCM is aware of early ignition of the fuel. Gas engines use knock sensors to determine detonation. I have no idea if diesels have these sensors or something similar.

Cetane boost typically also oxidizes fuel prematurely, so treated fuel cannot be stored as long without degradation.

 

There are a lot of diesel engines using the Bosch CP4 pump. VW TDI's do. However, they are single-pumper designs vs our twin piston designs (obviously the smaller engines need less fuel volume).

The early design CP4 pumps were very susceptible to rusting in the presence of moisture. Later versions (2015+ our trucks) saw the pistons and / or cylinders coated with a special film or coating which enhanced lubrication. Obviously, any moisture would reduce the lubricating properties of diesel, and thus the PM22 also restored a small amount of added lubricity. But the real problem is the ULSD simply doesn't lube as well.

When I use PM22, I *never* see better fuel economy, regardless of what season I'm in or if I'm towing or not. I only use it because of the hope it might add a little bit of extra lube in the fuel pump.

 

That is good data, thanks.


As far as PM-22 use, I feel the same way. I am mostly after the lubricity improvement, if there are other ancillary benefits(fuel economy etc..) then great.

 

German diesels, like the VW TDI love a Cetane of 50, and what a huge difference in power, smoke, and mileage. Every tank I add it to all my VWs, and I can tell when I don't. My new SD will have it, it's cheap insurance for a cleaner burn and less soot in my EGR....Grrrrrr.

 

In Texas the minimum centane is 48.

Texas Low Emission Diesel (TxLED) Program

TxLED must contain no more than 10 percent aromatic hydrocarbons by volume and must have a cetane number of 48 or greater, or else must use an approved alternative formulation or comply with the designated alternative limits.