cethane

The "H" in my username is for HIGH (as in High Cetane). I've had diesel's since my very 1st car and have found that the higher the cetane rating the better the mileage. The higher cetane seems to ease cold weather starting (at least in my MB diesels). I almost always fillup with Texaco Premium 45 cetane or the Amoco 47 cetane (they used to have a 50 cetane). I also add either the Standyne or the Rotella DFA which increase the cetane 2-3 points. The worst mileage I've gotten in my CTD was on 40 cetane from an off-name truck stop (they were nice enough not to charge extra for the water in the fuel )

phox_mulder

Utah doesn't require Cetane levels to be posted.<br>(I've never seen them anyway)<br><br>Prior to reading about them on this board, I didn't think there was any difference in Diesel from point A to point B, except maybe dirt or water levels.<br><br>All I know is if I fill up at the Chevron or Phillips near my house, my truck runs great, no discernable difference between the two, and similair mpg figures as well.<br><br>If I fill up at the Sinclair next door to the Phillips, my truck doesn't seem to have the power, and the mpg suffers.<br>(Did it once, haven't filled up there since, it might have just been a bad load, but once bitten twice shy or whatever)<br><br>Would be very interested to find out Cetane levels of those 3, but I highly doubt the counter jockey would even have a clue as to what I was talking about.<br><br><br>phox

Shovelhead

Gary, I usually only deal with 2 stations for fuel.<br>If I'm going on a trip, I'll fill my &quot;Poor Man's Aux tank&quot; (four 5 gallons fuel cans) and strap 'em down in the bed to avoid fueling up &quot;Blind&quot; if I can't find a Truck Stop.

Dieseldude4x4

I buy Texaco in Waverly. For whaetver reason, I get better mileage on my truck and on my little Neon when I buy their gas. I buy at Quarles in Front Royal which is pretty good fuel. When I travel outside those two, I always fill up at Waverly when I get home and add an extra dose of DFA too. Could be all in my head but it works for me.

AlpineRAM

Well, over here there are laws that are quite strict about all kinds of fuels. The minimum cetane number allowed to be sold is 51. Usually we have a little over 54. <br>The effects are easyer starts and less smoke. (Also depending on sulphur %) The lubricity is also in the requirements. <br>Now you might think that this contributes to the high prices over here- well maybe- but since 72% of what you pay is TAX and only 28% is for fuel, delivered to the station, the shop attendand and all the rest.... go figure. :'(<br>The costs for analysis and additives are not really high when divided by the number of gallons per lot. A friend of mine who works for an Austrian oil co. (Fuel specialist) told me that the costs for treating diesel to comply with the regulations over here are about 1,3cents per gallon for diesel imported from the bulk outlets in the US- as long as it's the lowest sulphur quality. <br>A good cetane and lubricity booster used over here is biodiesel. (not raw veggie oil, the transestherified stuff)<br><br>AlpineRAM<br>

WHIFF

[quote author=Shovelhead link=board=8;threadid=16598;start=0#156247 date=1057266449]<br>From duralt.com<br><br>cetane number <br>is a measure of the ignition quality of a diesel fuel. It is often mistaken as a measure of fuel quality. Cetane number is actually a measure of a fuel's ignition delay. This is the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels.<br><br>From Yahoo American Heritage Dictionary,<br>octane number <br>NOUN: A numerical representation of the antiknock properties of motor fuel, compared with a standard reference fuel, such as isooctane, which has an octane number of 100. Also called octane rating <br><br>[/quote]<br>Perhaps of note is that both cetane and octane are benzene rings of hydrocarbons, containing carbon-carbon double bonds (annotated C=C). It is the method of how carbon rings attach themselves together. During combustion, they break the double-bond apart, giving off energy.<br>Diesel fuel contains many types of carbon bonds, including paraffinic and napthalmic (other types of carbon bonds), as well as aromatic bonds (like cetane.) The aromatic bonds have more energy when they break apart (combust) which gives a better fuel efficiency.<br>Therefore, the higher the cetane number (ratio of cetane to other types of carbon bonds, e.g. paraffinic) the higher the energy derived from combustion, and the higher the MPG!!!<br>At least that's what my chemistry instructor always told me. It works the same way with jet fuel (which is pretty much like diesel.) I get a lot farther on JP-4 than JP-8 or Jet-A, due to the higher amounts of C=C bonds.<br><br>letmeputmysliderulebackinmypocketpro tectorWHIFF ;D<br>

AlpineRAM

Whiff: It's not only the double bonds, it's also the relative number of C to H. <br>More C - More engergy per mass when combining with O ;D <br>And since a = bond occupies the space of one possible H bond naturally there is more C in it per mass unit <br><br>AlpineRAM

Lightman

I certainly envy high cetane low sulfur Euro fuel, if you don't you're a moron. I don't envy their prices =] <br><br>The EPA standard for Cetane here in the US is 40. Average US fuel ranges from 40-42. Some states like CA, or metropolitan cities with emissions/smog issues, have switched to either ULSD (15ppm max sulfur) and have raised the cetane to reduce emissions. For example, all diesel in the Dallas area is 47 cetane minimum. I'm not sure about Houston, as someone asked earlier. <br><br>Most diesel fuel in the US comes as a standard 'fungible' product down pipelines or off barges, and is additized and branded at terminals. There a few companies that do keep their fuel separate every single step of the way, which is why these premium fuels demand a slightly higher price. BP Diesel Supreme and Amoco Premier are two really outstanding fuels. Low sulfur, 50 cetane minimum, and a really robust addtive package - with lubricity enhancers, anti corrosion additives, etc etc. They are unfortunately available only in a few states. There are also many mislabeled pumps across the country, however REAL premier or supreme is only sold around the midwest area. www.bpdirect.com has more info.<br><br>Other companies have what they call 'premium diesel', which just means it has to meet a few out of the 5 or so requirements to be labeled premium. Citgo, Sunoco, and Texaco meet the requirements to be labeled 'premium' because they have additive packages that meet the thermal stability and injector cleanliness standards. They also claim lubricity additives, etc are in their fuel. Texaco is the only premium that has a cetane booster, and is usually min 45. <br><br>Subjectively, I've had crappy results with Citgo anything, and Sunoco diesel.<br><br>Objectively, in my local area(FL) where bp supreme or amoco premier are not available, my fuel tests and others' have shown that Hess consistently has the highest cetane diesel in the state. I'm still waiting to hear back from Hess about their distribution, however it was rumored that Hess keeps their fuel separate.. One thing to note is that some companies allow independent station owners to source their own diesel, thus there is no consistency in the quality of the product, although the tanks' condition remains the same. I know for a fact that Hess only allows its stations to carry Hess fuel, whether independently owned or corporate. <br><br>Sheesh, what a novel. Sorry folks, I get into all things diesel ;D

Lightman

One more thing I should add...you guys that actually can GET BP supreme or Amoco Premier, D*(&amp;^&amp; you, I'm jealous <br><br>Some have suggested that the increase in cost doesn't justify the increase in cents per gallon. I think that's short-sighted. With the premium you are also providing extra lubrication to your fuel injection and extending it's life, as well as reducing buildup (higher cetane=cleaner combustion), AND EMISSIONS. Higher cetane/lower sulfur means lesssmoke and pollution.

angleiron

I have a BP station right in town that seels the premium diesel, but they are about $0.10 higher than everyone else. I guess maybe that extra dime may be worth it, so I will have to gve them my money for a tank of fuel to see if it truly pans out.

Lightman

Gary, I'm not sure how to what levels in each category the fuel must meet to make it qualify, but a gallon to a tanker, I'd bet that it wouldn't. Mislabled fuel isn't anything new. There are amoco premier labels on pumps down here in florida and amoco doesn't sell premier anywhere near florida... False advertising, unfortunately common.. <br><br>Angleiron, where do you live? Is it called BP Diesel Supreme? One way to rule it out is if it has any color. Supreme is as clear as water, with no color. Just because it's clear doesn't mean it's supreme, but if it's another color, you know it's NOT

angleiron

I live in Illinois, and it is advertised as &quot;premium/low sulfur&quot; diesel. I have a Pilot that is a few miles away that is a large truck stop and they sell their fuel for $0.11 a gallon cheaper that BP. I am getting about 20mpg on my new truck now (highway/city with A/C on). I have a hair over 2500 miles on her, so I guess I am not doing too bad. When hauling my 4500# boat, I am getting a little over 17mpg...but this is going 65mph