So if ULSD has lower octane then what are u guys using to increase the amount of octane in your fuel?

 

Diesel is not dependent on octane. For diesel, the cetane rating is what matters.

As pointed out however, sulfer content is not the issue with available power fora given quantity of diesel. Theprocess used in creating ULSD stripstheamount of some of the aromatics, which is the cause of the lower specific power per quantity.

The current push to replace lead substitutes in gasoline (specifically MTB, whichwas used to increase octane) with alcohol has decreased the amount of power available from the gas, so although the octane rating is still there, the amount of power is lower, so your mileage suffers. There's also other nasty issues with alcohol that are not particularly good for engines either. Alcohol absorbs water, so the potential issues are obvious. However, with that said, a 10% content of alcohol may not be sufficient to cause water problems with internal components.

Another issue with alcohol is its effect on rubber and polymer fittings, etc. Alcohol is bad for them and will cause premature failure. Again,I'm not sure a 10% content of alcohol though is significant enough for this tobe a real issue...only time will tell.

 

Oh, while we're on this subject of fuels, I got a bit ofa surprise the other day. I stopped into a Shell station and was surprised to see a small sticker on the diesel pump that said it contains 20% bio diesel. My 04 CTD, according to manufacturer, is only rated to accept up to 5% bio. Unfortunately, there was not another station within driving distance with the amount of fuel I had in my tank, so I put a few dollars of the Shell diesel in, then headed for another station and filled up with the "real" stuff.

I don't know if all Shell diesel is like this or not...I've not bothered to stop at another to check. Anyone else seen this?

 

I haven't seen that sticker yet. Was the price of the fuel the same?

 

More or less in the same price range as all the other stations selling diesel. I also notice the Shell stations here advertise their diesel as "Premium Diesel". Premium diesel is supposed to have a higher cetane rating than "regular" diesel (diesel is required in the U.S. to have a minimum cetane of 40 and "premium" diesel is supposed to 49-55 cetane I believe), but that information is not on the pumps like octane is on gas pumps. Since they seem to be selling 20% bio, that may make sense as bio/vegetable based oils have naturally higher cetane ratings than petro based oils due to higher oxygen content.

The issues with higher bio content has more to do with getting proper flow and pre-heat temps for the oil. If you wanted to, you could purchase a convertion kit for your CTD and run vegetable oil in it just fine. It does require a little more maintenance, etc, but if you had a good source for oil (usually restaurants getting ridof frying oil) and didn't mind filtering it, it's a very cheap source of fuel. Power output from veggie oil is on par with pump grade diesel. I have a friend that puta convertion on his old mercedes diesel car and filtersoil he gets from local restaurants. With the cost of his filtering equipment and the convertion parts for the car, his "fuel" is costing him somehting like $0.30 a gallon over time. The funny part is, the car smells like a french fry going down the road. Also, with these convertion kits, youstill have to have a diesel fuel tank. You start the engine on diesel and run it on diesel until the veggie oil gets heatedto a certain temp, then you switch it over and run on the veggie oil. You switch it back to diesel to flush the fuel system and have diesel available for the next start up.

 

My original plan was to do a 1 tank test but the 4mpg differance did seem like a lot so changed the test to 4 tanks with the same results (hand calculated)

I normally have about 1,500 lbs in the bed.

 

OK! I mis-stated what I meant. If the centane rating is lower for ULSD, then what are you guys using to bring it up to par with LSD fuel. PS, lucas, etc. I've tried a few but haven't seen a good enough improvement. All suggestionswelcomed.

 

hmmm.... well reading what has been written so far I guess I'm backwards. I bought lsd a while back and then bought ulsd the next time. I thought I could feel an increase in power while using the ulsd, so I haven't ever even looked for lsd anymore. I go to the same station everytime now (moto mart) and get the ulsd, I am throwing in some drews brew now too, but I wasn't at the time when I noticed these results.

 

4 mpg seems like a huge difference..I have ran both and not seen any meaningful difference in fuel mileage. (I'm running B5 ULSD now) Since there aren'tmany trees or real hills to speak of in southwest kansas.. the wind plays a big part in my fuel mileage.. IbetI couldsee a 4mpg difference depending on the direction I'm driving and the wind speeds. Maybe the difference you are seeing has more to do with driving conditions than LSD vs. ULSD.. or at least it's playing a part.. What hurts me most is that uncontrollable desire to spool the turbo up while passing cars on the highway.. it's like a jet taking off.. no shifting gears.. just pushes you back in the seat [sm=drooldude.gif]

 

I got LSD for the first time in N.C. on the way to Kentucky and I got 19 miles a gallon by hand going up and down mountains at 75.

I can't get LSD around me in Florida so I have no way of comparing on the flat ground and around town driving.

I was getting almost 600 miles per tank, so it made the 740 mile trip faster as I only had to fill up once, instead of three times like in my Dakota, My brother called at 9 am and I was still getting ready to go and left at 9:30was sitting there in ten and a half hours. my sister-n-law asked how I made it so quick