Are there grades of Diesel Fuel?

[drh1965]

That is, are all diesel fuels created equal? Is there such a thing as marine diesel, for instance?

[swagman]

Yes, apparently there is.

I speak not from specialist technical knowledge, but rather from a long thread a year or so back on another sailing site.

The guy who gave the good oil worked for a fuel wholesaler - and in summary explained marine diesel fuel had a different sulphur content to other fuel oils. Lot's of others argued with him, but he appeared to know what he was talking about - even providng the differing formulations for heating, truck, marine and other specialist diesel fuels.

But having said this, confess we've used marine and regular truck diesel in our tank - and it did not appear to be much different to me!!

Cheers
JOHN

[CSY Man]

I have always used diesel fuel from the neigborhood gas station.
Less work to haul a few cans in the back of my truck than to dock at a marina and get fuel.

Did not know there was a difference....?

[mickmul]

A pigment is sometimes added to distinguish between "agricultural" and "road" diesel. Both attract different excise duty rates (in Ireland at any rate), and are also sold as "red" or "green" diesel - (the red or agri being used for boats) - I've used both and never had problems . . keep your tanks topped off in colder weather to prevent condensation, check your water filter/seperator, and motor on!

[Gator81]

I know nothing about marine diesel applications, but here in landlocked Utah, there are just two forms of diesel fuel. As noted above, the difference is only in the color of the dye added to indicate whether road tax has been paid or not. Diesel fuel for any vehicle that is licensed to operate on public roads must have a substantial tax paid (something like 40 cents a gallon) whereas the same fuel bought for ag or construction equipment need pay no road tax.

I know a lot of guys who drive diesel pickup trucks, with fuel tanks in the back which they fill with untaxed diesel, supposedly for their "tractors". But I notice the hose on that tank will reach the truck's fill neck...

[JohnnyC]

Check out this link www.epa.gov/otaq/regs/nonroad/marine/ci/fr/dfuelrpt.pdf


If I read this correctly there are many "Diesel" fuels. Most of the differences are for commercial diesel fuels used in cargo ships etc. What is sold to recreational boaters is fuel oil #2. This is basically the same as the diesel sold in auto filling stations and as some home heating oil. I say basically because there are differences in sulfur content mandated by law for these fuels in some countries. What is sold for recreational marine use actually varies according to what is readily available in your area. It may be the same fuel put in your Ford or GM diesel truck (generally low sulfur) or the same oil heating your home (less refined, higher sulfur and better lubrication for your marine engine). Sometimes marine diesel is dyed a different color to indicate tax levied on marine users.

Bottom line seems to be that any fuel oil #2 will work.

[sluissa]

I didn't realize it either until I had read an article about a diesel car that could supposedly get 200+ miles to the gallon, but finding fuel for it was incredibly hard because it required a super low sulfur content.

[drh1965]

Very interesting... the reason I brought this up is that I've read that the Sulfur content in diesel fuel effects lubricating ability of the fuel (indirectly). I've also read that it is possible that pre-1988 diesels might have problems with the lower sulfer content diesel fuels for this reason.

Based on the article posted, it would seem that the Intermediate and Residual fuels would be best for older diesels. Further, it also seems like it would be very difficult to determine what type of diesel a given marina gas dock would be supplying. I suspect asking would result in a blank stare followed by something to the effect of "diesel is diesel"

[Pura Vida]

Darrell,

Recent changes in US regulations have created a market for Ultra Low Sulfur fuel for passenger cars and light trucks. Most fuel retailers are switching over but the older, higher sulfur content fuel was still available at the Buckees on HWY 96 just a couple of months ago. If you own a current modle year diesel pickup or car be careful where you buy you fuel or it may void the warrenty. As an aside it takes me a long time to burn up a tank of diesel so stabilizer and biocide are important. This Chevron information may help out.

Diesel Fuels Question and Answers - New s15 ULSD Regulations

[Alan Wheeler]

OK, lets clarify this. The Diesel Fuel oil itself, is a specific viscosity. I can't remember the actual figure off the top of my head, but supposedly, all Diesel is supposed to meet a certain
"same" standard. So it would be like say, a 30W40 oil for instance. But from then on, specific fuels may differ. Quality is one huge difference for instance. The quality I refer to here is from the base product. Not all oils out of the ground are equal. Some have a very high natural Sulfer content for instance. NZ for instance, imports a very low sulfer content fuel. Then oil refining companies will "play" with the base product to get the final quality they require. This often has a great deal of influence by each countries Government polocies on polution. Once agin, here in NZ, we have a very low sulfer content, with even further sulfer now being removed from the base product and the view that all sulfer will be removed by a certain date.
Then additive packages are added, just like engine oil. Some countries with extreme weather temperatures, will have summer and winter fuels, so as the fuel does not solidify as easily in the winter. With the physical removal of Sulfer, certain aromatics also are removed in the process. So other chemicals are added to keep the fuel stable and lubricate. Although many of us know, fuel does not last as long as it used to. Then as already stated, some countires like the UK and the USA have red dies added to show taxed and non-taxed fuels.
So no, Diesel is not the same and can be very different from place to place to place and country to country.
Interestingly, 20yrs back, Diesel was of such poor quality, that many of the fuel additives available worked extremely well at solving many issues. Such as stopping black smoke, increasing power and decreasing fuel consumption. With todays vastly cleaned up fuels, it is mostly impossible to get anywhere near the claims that used to be made by most of the additive companies. The days of fuel additives making performance improvments are long gone.

[jdoe71]

In the frozen great white north we have different grades of diesel for summer and winter. Chief difference is winter stuff is less likely to gel in our pretty cold winters, though other than in the Yukon and the NWT, er, ah, I guess they call it Nunavut now, that's becoming less of a problem thanks to global warming. I have used each in opposite seasons in my field tractor with little apparent difference other than the winter grade seems to not get quite as good "mileage" as the summer. Some folks suggest the winter fuel is better in boats since it is less likely to precipitate out "gunk" but I have no idea if that is true or not.

[Amgine]

yes, there are many forms of diesel oil.

In north america, the two primary forms of retail diesel are #1 and #2. In layman's discussion, there's very little apparent difference except that #1 fuel has a lower "gelling" temperature. (When cold enough, diesel oil will "gel" becoming a more viscous fluid similar to motor oil, and much more difficult to filter and pump, so diesel fuels are variously blended or straight #1 in winter.) There is a measurable difference in energy output between the two fuels; you can get slightly more miles per gallon from #2.

Some people feel there is a difference between "first crack" and subsequent distillations of petroleum oil. First crack fuels are those made from the first time crude oil is processed, so they're the easiest to get. Second crack and subsequent distillations require progressively greater heat and pressure, as well as other processing, to meet the standards for fuel grades. In general, the economy fueling stations tend to have these later distillations as there is a tiny premium paid for first crack fuels.

(The primary differences between "brands" of fuels are the additives to the processed fuel, rather than the methods of their refining or the standards to which they are processed. To exemplify this, most markets have all brands being produced from a single refinery.)

Dyed fuels relate to their tax status. In most countries, red dyed fuels are untaxed, and are primarily for agricultural use (a form of agricultural subsidy.) Heating oils (which may be different standards than #1 and #2) usually have a different taxation compared with diesel oils destined for road use, and may be dyed. Taxed oil may also be dyed; for example Ireland dyes road-use diesel green.

While the hydrocarbon ratios are the primary measurements used to establish different "grades" of diesel, there are actually several different standards of lubricity within diesel fuels. In most diesel engines the fuel serves a very vital part of the lubrication of injectors, and the failure of most national grading systems to account for lubricity means not all diesel fuel which meets the grade will also meet the engine's requirements for lubrication. This is one point where biodiesels are better than petroleum diesels; they have a higher lubricity ratings, indeed some manufacturers think they may have too much lubricity.

Anyway, a mis-spent youth growing up in my father's gas stations.

[jdoe71]

Interesting info Amgine. We have red dyed diesel for off road which I buy for my tractor, and the road stuff looks green to me. They sell the road stuff at marinas, the truck that fills our marina up goes across the street and fills the gas station up as well. Only difference is the red has no road tax on it so why marinas can't sell it I don't know. I'm pretty sure our furnace oil is almost clear maybe a little yellow, it was 72.9 cents a litre a year ago. Just lately I paid about 80 cents a litre for red dyed (no road tax), 94 cents a litre for green on the highway (road tax plus prov. and fed taxes calculated with the road tax in, tax on tax, sweet) and last week anywhere from 1.19 to 1.29 a litre for green from marinas (also taxed same as highway). Gotta love the tax structure and the lack of any kind of sense, why would boats pay road tax? They're big serious about it though, the provincial govt has diesel cops who go around dipping fuel tanks looking for red fuel and the fines can be huge if you get caught. And up here you are pretty much guilty until proven innocent for a provincial offence.

So do you or does anyone else have any info on the suggestion that #1 winter fuel is less likely to precipitate gunk out of it? The person who told me that said it was because the stuff that causes gelling is also the stuff that is the first to sink to the bottom of your tank and become sludge.

[Amgine]

I personally never noticed any benefit for #1 reducing gunk, although I seem to recall my Dad saying something about it "cleaning out the tanks." That may have been an urban (or in his case rural) myth.

I don't know if Canada dyes road tax diesel; I grew up in Minnesota USA. According to the Petro Canada site red-dyed diesel (off-road) is the only type they talk about. Interestingly, regular sulfur diesel is the usual red-dyed diesel, and it is listed as used for marine purposes in Canada.

[Steve Kidson]

A mate of mine used to own a fuel distribution business in a regional area of NSW - Australia.

Many of his customers were long distance truck drivers who were able to tell by the performance of their trucks, the quality of their fuel. As a distributor or fuel station, you have no control over the quality of the fuel - its what the oil company delivers!!

There is a "summer" and "winter" mix, and while I don't know the formulations or reasons, the truck would noticably underperform if summer fuel was used in cooler conditions. Under-performance was more noticable the greater the load or torque requirements of the journey; ie long uphill runs with heavy loads.

Not sure if if it makes that much difference in our boats, as we (sailors) primarily use our engines for getting on/off moorings or in/out of marinas or other berths.

Fair winds

Steve