Diesel Newb Question

RTStabler51 · **Posted:** Mon Jan 09, 2006 9:34 am

Forgive the ignorant diesel question, but what are the differences i nthe diesel fuels out there? I see lots of references to B4, B5, B20, etc. When I look at my normal fuel station, I don't see any 'B' numbers, just a Cetane rating. Can anyone help a brother out? Just looking for a simpleton answer. I know they are different blends, but after that I'm clueless.

Thanks!

Rick Miley · **Posted:** Mon Jan 09, 2006 9:38 am

When you see a B in the designation it is biodiesel. The number indicates the percentage of biofuel in the mix, B20 is 20% bio and 80% petroleum diesel.

retmil46 · **Posted:** Mon Jan 09, 2006 1:05 pm

And as far as cetane numbers, get the fuel with the highest cetane number that's available. Higher cetane generally means higher MPG.

dog_party · **Posted:** Mon Jan 09, 2006 1:11 pm

That's not an ignorant question at all. Rick explained it well. To elaborate: The cetane number measures the ignition quality of a diesel fuel. Basically, cetane number determines when the fuel will ignite. Most on-road diesel engines are timed to use cetane numbers between 40 and 60. Anything above 60 is wasted. Anything below will make your engine really noisey.

Biodiesel is fatty acid methyl esters (FAME), which is derived from a number of different renewable resources. Rudolph Diesel originally used peanut oil (with help as the secondary resource). Today most of the American bios come from soybean oil, with rapeseed oil being the most popular in Europe. That's not the same thing as waste vegetable oil (oil used straight from a deep-fryer). Bio is veg oil with the glycerins pulled out (which are then used for soaps). It's a very clean and renewable resource and you'll LOVE it after you put it in your truck. Your truck won't smoke and will pull harder than it does with regular diesel.

Jeep reportedly says B20 is the highest bio mix that you can use in your CRD, but that's only because they can't verify the quality of a lot of higher rate bios being sold across the country.

Petro diesel is what you're seeing at most fuel stations. It's pulled from the same dino-derived oil that gasoline is, just at a different distil point. It's normally cetane 40 or 41 (cheapest thing they can get away with). Just try a tank from each station and document which one(s) are good and bad. Steer away from stations that do oil changes because there is no law to prohibit them from dumping used motor oil into the diesel tank. Look for stations that do a lot of diesel business. And look for stations with above-ground tanks if you can find them. Above-ground tanks are good because water won't seep into the tanks like it can in underground tanks.

If you want to try bio, you have a number of options up there in the DC area. Winchester, Arlington, etc., etc. Click HERE for a list.

Good luck!

RTStabler51 · **Posted:** Mon Jan 09, 2006 5:16 pm

Thanks for the link! Looks like I have some readin' up to do!

dog_party · **Posted:** Tue Jan 10, 2006 8:51 am

Quote:

Rudolph Diesel originally used peanut oil (with help as the secondary resource).

Oops, just realized my typo...I meant to say, "with HEMP as the secondary resource."

Another good reading resource is HowStuffWorks.com. That link goes to the diesel engine page. From there you'll find links to biofuel info.

Post any questions RTStabler51! There are no stupid questions!!

Guest · **Posted:** Tue Jan 10, 2006 9:15 am

retmil46 wrote:

And as far as cetane numbers, get the fuel with the highest cetane number that's available. Higher cetane generally means higher MPG.

There are no cetane numbers posted on any diesel pumps up here in the Indy area. Even supplier websites don't post their numbers so I feel like I'm in the dark when it comes to fuel quality. Any suggestions on how to actually find out what a particular truck stop has - the attendants working there don't know.

wenied · **Joined:** Wed Dec 21, 2005 4:01 pm **Posts:** 107

There aren't any cetane numbers posted here either. Furthurmore, all stations here use the exact same diesel. Citgo refinery is right down the road and they're the ones that supply diesel to all stations in my area. There is also a conoco refinery but they do not make diesel.

vtdog · **Joined:** Fri Sep 30, 2005 11:27 am **Posts:** 640

I generally use Hess diesel because its up to 20 cents/gal cheaper than the shell station and they pump alot of trucks. The pump is posted 45 cetane/ultra low sulfur/high detergent. The Hess rep (not the pump jockey) told me that the fuel can actually vary in cetane rating from 42-48, but that the winter blend would always be present in cold months.

oldnavy · **Posted:** Tue Jan 10, 2006 10:51 am

If no Cetane # posted, it is most likely 40 to 42 cetane fuel, of which 40 cetane is suppose to be national minium.

The problem with buying from palces like local service stations is not only stale fuel, but service stations often dump their used motor oil into the diesel fuel underground tanks to avoid having to pay to have it removed for EPA standards. At large major truck stops this is frowned upon as it hard on the engines and if discovered the OTR rigs will not stop for service, however it has been known to happen. I even got a bad tank like that once at a truck center on I-70 west of St Louis MO several years ago in my VW diesel. Luckey for me I only bought enough to get home on and was able to top off with good fuel later and change fuel filter before any damage done. I managed to kill every flying bug within 50 yards of either side of the highway all the way home.

wenied · **Joined:** Wed Dec 21, 2005 4:01 pm **Posts:** 107

I'm not sure if it's the same everywhere but here the oil change places get paid for the used motor oil. My buddy owns one of these stations and he tells me they get 10 cents per gallon and that actually adds up to a decent profit after a month of 75-100 oil changes a day. He typically sees about 150 to 200 dollars a month in profit from selling the used oil.

dog_party · **Posted:** Tue Jan 10, 2006 11:39 am

Quote:

I managed to kill every flying bug within 50 yards of either side of the highway all the way home.

I had the same bad tank of fuel thing happen to me and it was at a truck stop. I just love your description though! Ha! I really loved the looks I got driving home like that. Most people roll their windows down and stare at the rumbling Jeep when it's NOT smoking like a tractor. Leave a 100 yard plume of black smoke everywhere you go and THEN check the stares! Ha!

There really should at least be a big green "40" printed somewhere at any station that provides diesel. From my understanding that is the national minimum. Of course, what they mix in there with the 40 that was delivered to them isn't very well regulated. Buyer beware and make note when you get a bad tank and REPORT it! Report them to the BBB and make note here in the CRD section of LOST.

oldnavy · **Posted:** Tue Jan 10, 2006 11:46 am

Yes but I was in a white VW New Beetle that was less then a year old and when I got home it was covered with black oily soot from top of the fenders across the back of the car half way up the back window. I other words I had a two-tone car when I got home. :evil:

LibertyCRD · **Posted:** Tue Jan 10, 2006 12:14 pm

If cetane increases mileage, why does my mileage drop when I add cetane boost additive (power service in the white bottle) to my tank??

retmil46 · **Posted:** Tue Jan 10, 2006 12:19 pm

Cetane rating isn't on the pump here in NC either. You have to do it the old fashioned way. Ask the station owner, distributor, etc, working your way up the chain until someone can give you a concrete answer. If you're lucky, you'll have a company like Flint Hill Resources with a website that not only lists the cetane rating and other specs for their fuel, but also shows where all their refineries, terminals, distributors, and retail stations are located, along with contact info for their area reps. These are the guys that make Arctic Express and Premium Gold diesel.

Flint Hill rep for NC is the one that told me to give Hess a try. He said his company didn't sell to that many retailers here in NC, and he hated to send me to a competitor, but that in this area A T Williams Oil Company in Greensboro was Wilco-Hess's major supplier of diesel, and they did make a good grade of premium diesel.

In the eastern 100 counties of Texas, you guys are lucky. The new TxLED requirements (check at http://www.biodiesel.org ) specs that all diesel sold in that area has to be essentially ULSD with a cetane rating of 48. Perhaps that's why Diamond Shamrock gave such good results on my trip.

RTStabler51 · **Posted:** Tue Jan 10, 2006 3:53 pm

Well, I just filled up with a tank of B20 at the local place in Arlington for 2.90 a gallon. We'll see how she does on the road trip this thursday.

dog_party · **Posted:** Wed Jan 11, 2006 8:25 am

Good pick RTStabler51. I was planning to fill up at that station the last time I was up in DC, but I ran out of time. How easy/hard is the station to access?

naturist · **Posted:** Wed Jan 11, 2006 9:09 am

LibertyCRD wrote:

If cetane increases mileage, why does my mileage drop when I add cetane boost additive (power service in the white bottle) to my tank??

Because, simply put, neither cetane nor cetane rating has anything whatever to do with mileage.

Strictly speaking, cetane rating is ONLY a measure of how quickly the fuel ignites after injection, and it will determine noise level and ease of starting. Period.

There is some speculation that increasing cetane will increase mileage as an indirect function of earlier ignition giving an effect somewhat like advancing the spark on a gasser. This is unsupported by the evidence, however. I would refer you to the simple fact that biodiesel, with cetane ratings above 50, has about 10% less energy available per gallon, which always delivers decreased mileage, not increased mileage on honest tests, some folks reports to the contrary not withstanding.

RTStabler51 · **Posted:** Wed Jan 11, 2006 9:50 am

dog_party wrote:

Good pick RTStabler51. I was planning to fill up at that station the last time I was up in DC, but I ran out of time. How easy/hard is the station to access?

Its fairly easy if you know the area, I work fairly close to it. I think technically you are suppose to be a military member or a Gov't employee to use the station since its a Navy Annex gas station. However, being prior military I used it anyways. No one bugged me and I just swiped my card and it asked if I was 'authorized' and I was :-)

dog_party · **Posted:** Wed Jan 11, 2006 11:21 am

Good info from both Naturalist and RTStabler51.

Naturalist is right, cetane doesn't have anything to do with fuel mileage except to mess it up if it gets too high or too low. Most high-speed OTR engines are timed for 40-50 or maybe up to 60. Being in America, I'd say we're timed for 45 or less. If you're pumping cetane 45 or so, I wouldn't add any cetane boost. Adding cetane boost to fuel that is already at the cetane level that you engine is timed for will drop your mileage.

But, if your engine is clattering a lot, try adding some, you might be running low cetane fuel.

Thanks for the info RTStabler51. I didn't know that was a Navy Annex station. Try and couple fillups there and let us know how it does. I noticed a diffference after my first tank of B20.

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