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View Full Version : Crazy, "What If" question?



waynep
03-19-2007, 13:22
Hello All:

Yes, I know it is not legal and we all have to breath the same air, BUT, what would happen if one were to put sulfer back in to diesel fuel to reach pre no sulfer levels?

1. How much would one use?
2. Would it help performance, milage etc?
3 Potential for damage besides being totally wrong and illegal?
4. Would it help lubricity?
5 Cetaine rating etc?
6. Effects related to 6.5 turbo diesel? vs Duramax?

Just wondering.

THank you

DmaxMaverick
03-19-2007, 14:00
Bad idea

The sulfer is not the desirable content of the fuel. It is not a lubricant. It's BTU potential is lower than pure #2. Sulfer will not increase cetane. It will not improve economy.

Low and ultra low sulfer fuel lacks lubricity because the process to remove the sulfer, also removes/disrupts lubricating qualities. It is not the sulfer itself that is desirable.

The best solution for low cetane, poor lubricating fuel is to replace what is missed. Lubricating (fuel additive or other lube) and cetane improving additives are the most practical remedy.

More Power
03-19-2007, 14:00
Sulfur is irrelevant to fuel lubricity. The added hydroprocessing used to remove the sulfur is responsible for reduced lubricity.

Use a commercial fuel additive that includes a lubricity ingredient, cetane booster and injector cleaner. A cetane booster usually raises fuel economy enough to pay for the cost of fuel treatment (numerous fleet fuel economy tests have shown this). :)

Jim

billschall
03-19-2007, 18:38
If you're concerned about the loss of lubricity, why not just run any of the various flavors of biodiesel? Even B5 overcomes the lube-loss of LSD & ULSD.

waynep
03-19-2007, 19:38
Hello All:

Thanks for the answers. Now it makes more sense, as I could not understand how a little sulfer could make such a difference in lubricity etc.

Yes, I run 20% biodiesel and so far no problems. I also use an additive just in case as I am now on my third IP and the warranty will not cover then next one.

moondoggie
03-20-2007, 11:03
Good Day!

"A cetane booster usually raises fuel economy enough to pay for the cost of fuel treatment (numerous fleet fuel economy tests have shown this)." Please, urls, links, etc. - I'd really like to see actual test data that proves anything improves mpg. I can do the math myself to determine if it's cost-effective. I've just never seen any hard data.

Thanks & Blessings

More Power
03-20-2007, 16:17
Stanadyne ran a number of fuel economy tests in the 90's involving fleets of diesels - some trucks ran with and some without a fuel additive. Most of these longterm tests showed some percent increase in fuel economy when using a fuel additive that included a cetane improver.

It's pretty hard for an individual to see (be sure about) a slight change in fuel economy due to changing conditions and vehicle use over time. Compound that with variable fuel quality (different fuel stations and refineries). Bosch measured diesel fuel cetane all across the US in 2002. They found cetane varied between 44 and 57. That's a big spread. ASTM certified diesel fuel must test at 40 or above. Fleet tests are the best way to document changes in fuel economy due to a fuel treatment.

Jim

JohnC
03-20-2007, 16:45
About 10 years back I was driving the same routes every day day in and day out. I kept track of every drop of fuel I bought. I recall that the increase in mileage almosty exactly offset the price of the Stanadyne additive is was using. I don't remember the exact numbers, but I think it was on the order of a 3% improvement. Sorry, no url's...

DmaxMaverick
03-20-2007, 19:38
Same here. No URL's, no scientific comparison charts or graphs. Just my experience. I did a similar comparison way back when Diesel was under $2/gal. I was ahead of break even then, using PS gray bottle. The savings increase with fuel cost increase. I've used it so long, I can instantly tell when I forget to add, or run out. It shows in economy, sound, and performance, especially towing.

moondoggie
03-22-2007, 11:08
Good Day!

The variable mentioned by More Power is why I keep hoping someone can point to independent, scientifically-collected data proving that any additive improves mpg.

I can do the math. Stanadyne PF (Performance Formula) claims I'll see a 3 - 8% mpg increase. If I get 20 mpg now, paid $120 for a 5 gallon pail of PF, use 8 oz/ tank (~ correct ratio), buy ~ 30 gallons of fuel per fillup, & am paying $2.75/gallon of diesel fuel, I only need to see ~ 2% increase in mpg for the PF to pay for itself. So, if I see Stanadyne's claim come true, the stuff more than pays for itself, & I get all the other benefits of PF for free.

Unfortunately, I ran 5 gallons of PF through my pickup at the recommended rate, & my mpg went down slightly. As MP says, the variables he mentions, & MANY more, affect mpg too much for a test like mine to mean much of anything. Problem is, my mpg not only didn't go up, it went down. It only dropped a couple %, but this still doesn't encourage me to continue its use, so I didn't. (I now run 4 oz of Lubricity Formula per tank to counter low-lubricity ULS fuel.)

Again, that's why I had hoped for scientifically-collected data. :( The real frustrating thing is, I have access to instrumentation that would allow me to collect such data, & no time to do so. :mad:

Thanks & Blessings! :D

rustyk
03-23-2007, 21:27
Sulfur does increase the lubricity. But one can't just dump sufur in the tank - the sulfur is bonded to the fuel molecules as the crude comes out of the ground.

billschall
03-24-2007, 10:36
Sulfur does increase the lubricity...

Low Sulphur Diesel and Lubricity Issues:
Hydroprocessing removes sulfur and significant amounts of polar and aromatic compounds that give conventional diesel fuel adequate lubricating capability. Low lubricity in diesel fuel can cause engine problems unless treated with additives. Measurement of diesel fuel lubricity characteristics is important in order to monitor lubricity additives and final fuel quality.


http://www.intertek-cb.com/newsitetest/news/hfrrlubricitytest.shtml