I was talking to a local fuel company, the guys title was energy division manager. Anyway sounds like he is the guy that buys and keeps track of all the different fuels they purchase. I asked him what their cetane rating was on road diesel, he said 48. I thought I read somewhere, Ford or the manual, that you wanted at least 40. This manager said the ASTM minimum is 40 before its allowed to even go to the pumps. So now I'm wondering if it was 50? I tried googling it and check the tech folder. Anyone help me out on this for the 6.7L?

 

Cetane ratings are kinda like octane ratings. If you have a car that recommends 87 octane, will it run on lower octane? Sure, but maybe not as efficient. Would 91 or higher octane make it get better fuel mileage? Maybe but for sure would cut down on pre-ignition and detonation.

Similar for cetane. The higher the cetane the more efficient the combustion and power. The truck was designed to run on minimum of 40 cetane. Higher cetane will improve performance and to a degree mileage. Just like with a gasoline engine, once you achieve a certain performance level for the current ECU/PCM calibration, you will not see much if any gains. If you had a tuner that constantly calibration the injection of fuel according to the cetane and burn characteristics, you could see gains but would it be cost effective or prohibitive?

Most suggest you obtain high 40's on cetane if possible. Does going to 50 or higher cetane justify the cost per gallon per mile? Or does it make you feel better knowing you put in a higher cetane rated fuel?

You can also gain a few cetane at times by adding an additive such as Ford's PM22 or Stanadyne blue or red additive or some of the others on the market.

My thoughts, Buy the best cetane rated fuel for what you wallet can afford at that moment in time.

Hope this helps and is not too confusing.

 

I've read that while the higher the cetane level the better there is a ceiling at which adding more does not give any additional benefit. I did some searching but couldn't find the document so I can't tell you what that magic number is where raising the level won't be beneficial.

 

I run 50+ from the local Southern States coop. It is 5-10 cents more than other stations. I see a lot of big rigs filling up there so I'm pretty confident they have a high turnover to keep it fresh.

In my research #2 diesel is much like gasolines in that the base fuel is the same across brands and it is the additive package that makes the difference. With that in mind I feel like I am getting as good of a product as if I had added my own extra fuel conditioner for about the same cost without the extra hassle.

YMMV

 

This is correct. For the most part, all of the refineries (in Houston anyway) put their products into a pipeline and send it to a terminal, where fuel distributors will put in their additives package and transport to the retailers. There is no distinction between brands. The pipeline sets a spec in order for the refiner to have access to the pipeline. Sometimes we put in regular unleaded. Sometimes it is super unleaded, and sometimes it is Diesel, but it has to meet a minimum spec to be allowed in. There is no separation of individual refineries products within the pipeline. When it hits the terminal, it has some of everyone's product in the tanks.

 

Thanks guys, great info!

 

FWIW, California and some counties in Texas have minimum cetane ratings of 50. Folks from out of state said their trucks ran better on CA fuel than ever before. Europe has a standard of 51 and is moving to 56, I think and they have a higher percentage of diesel vehicles there. Higher cetane results in a better burn, less soot and better MPG. Ford says a minimum of 40 summer and 45 winter, and put out a video on PM-22A cetane booster that says they have found stations with cetane in the upper 30s. I've been running Opti-Lube Summer since my first fill up based on my findings after deciding to go diesel.

 

My understanding is that 'Octane Numbers (i.e. 87 - 91)' indicate a fuels ability to resist detonation. Only useful in high compression/performance engines. When I met my (now) wife four years ago, she was using 91 because the sales guy told her it (her car) would run better and get better mileage. I said horse pucky and pointed to the manual that said 87. She started using 87 and found no difference in performance or mileage saving big $.


""Octane" is colloquially used as a short form of "octane rating" an index of a fuel's ability to resist engine knock at high compression ratios". https://en.wikipedia.org/wiki/Octane


On the other hand, the Cetane rating of diesel is an indication of how easily it will ignite under compression. I can't say with any scientific proof that higher cetane numbers will increase mileage but my little gray cells seem to think it would. Easier ignition (particularly in cold weather) and faster burning would seem like (to me) an indication of more efficient and cleaner burning equating to better mileage. For the record, I add PM22 to my tank. Seat of the pants calculations seem to indicate I do get slightly better mileage. FWIW, I don't track mileage vs. fuel cost so I only have seat of the pants findings. The reason I add PM22 is to increase lubricity for the HPFP due to the low sulphur content in diesel fuel.


"Cetane is often used as a shorthand for cetane number, a measure of the detonation of diesel fuel. Cetane ignites very easily under compression; for this reason, it is assigned a cetane number of 100, and serves as a reference for other fuel mixtures". https://en.wikipedia.org/wiki/Hexadecane


"Cetane number or CN is an indicator of the combustion speed of diesel fuel. It is an inverse of the similar octane rating for gasoline (petrol). The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel's quality include (but are not limited to) energy content, density, lubricity, cold-flow properties and sulphur content". https://en.wikipedia.org/wiki/Cetane_number

 

Question...how do you separate the products in the pipeline? Run a batch then change.

 

They run what's called a pig, basically a plug, through the pipe between batches. Sort of of like the plastic barrier you use at the grocery checkout to keep your groceries separate from the person before you.

 

Not always correct here. Most of the time, nothing is used between different products in a pipeline. The material between the two products is downgraded or removed as transmix. Most all transmix gets re-injected into regular unleaded gasoline or re-refined. This is all monitored with flash points and specific gravities of the liquids.


Pipeline pigs are for cleaning, maintenance, and inspection.

 

ICE are tuned to run the best on a certain Octane rating. Higher Octane typically doesn't hurt, but it doesn't help either. I've found that different brands and grades of gas do better in certain vehicles. Always take me a few fillups to figure it out. I had a Dodge Gasser that only ran well on 87. Put anything higher and it got worse mileage and didn't seem to run right. Then we had a Volvo, would run the best of Chevron premium. Shell premium it didn't like for some reason...

Diesel, IMHO, the higher the Cetane the better. I can usually tell right when I pull away from the station if they are running 40 or 45. Even though most of the time I run additives. Sometimes when doing my long distance drives I don't feel like digging it out to put in. Especially if it is really cold/windy out.

There is a certain percentage of BioDiesel that doesn't make a difference. I forget what it is, but B20 is a good trade off point where the NOX emissions are not too high. I don't have to worry about it in Alaska. Too cold to run any blend a majority of the year.

I am curious about that other type of diesel California has. As to what it's cold weather ratings are. Instead of transtesterfication to get biodiesel they do hydrogen cracking. It seems to get good reviews from people that I would expect would give BioDiesel poor reviews.

 

Thanks for the clarification. Always nice to learn something new.

 

You are both correct. It is used for cleaning and for product separation. Just looked it up.

 

By law all CA diesel must have a cetane number avg of 53 across 5 samples. Also in the US, Chevron is the only company with dedicated pipeline and distro hubs
A Cetane rating above 50 begins to lose its percentage of effectiveness especially when comparing cost and effect. Ford recommends a Cetane number, not index, of 40.


Most states have adopted ASTM D975 as their diesel fuel standard with a minimum cetane number of 40.


BP (Amoco branded), 51
Chevron, 49 (51 with Techron D)
ConocoPhillips, 48
PetroCanada, 47-51
Shell, 46;
Sinclair, 46
Marathon 45
Exxon/Mobile, 43-46
BP, 40-42 (Powerblend 47)
HESS, 40-45
Husky, 40 (Max 41-45)
Sunoco, 40 (Sunoco Gold 45)
Holiday Stations, 40-43
Love's: 40
Pilot: 40
Valero: 40
Sheetz: 40
Flying J, 40