The fuel station I fill up my '97 F-250 at has switched from the LSD (low sulfur) to the ULSD (ultra low sulfur) fuel. Has anyone experienced any issues/problems running the ULSD in there 7.3??? I have read about potential issues on the amount of lubricant in the fuel, fuel mileage loss, etc. Thanks!!

 

From what I have read about it there isn't anything the ultra is going to effect on the 7.3.

 

My last two fills have been ULSD. I haven't noticed anything different. It's running really good.

 

More than likely you've been getting ULSD since 6-2006. The fill'em-up stations can't place the sticker on the pump until the underground tanks are inspected by the EPA.

Here's a couple links with more than you want to know about ULSD.

http://www.chevron.com/products/prod...ulsd.shtml#A13
http://www.clean-diesel.org/

 

I havent had any issues with the ulsd so far, but I have talked to a few diesel mechanics and they are getting fuel leaks comming in all the time.

 

I've noticed a small fuel leak for the last 2-3 months. Nothing serious, just a pain to find the source. I read somewhere the ULSD causes some fuel system seals to weaken.

 

I swear my fuel leak developed from using ULSD. Although I can't confirm it, but my 97 started a slow leak ever since I started filling up with it.

 

About the time my fuel filter was due for a change I had probably run 2 full tanks of ULSD through it, this was the first time in 10 years that my fuel filter was about the same color as my tires. You might check yours to see if you need to change the filter now.

 

The area I was living in had ULSD for a short time before I noticed a fuel leak. Then my fuel pump totally failed. When I tore everything down, I found that all my rubber fuel lines had gotten brittle and were cracked, there was fuel all over the valley, and the diaphragm on the low pressure stage of the fuel pump had also failed. There are unconfirmed reports that the ULSD lacks the lubrication that maintains our fuel systems -that whole topic is up for debate. I can only tell you what happened to me. When I was researching replacement parts, I found out that the new motors, that were designed for ULSD, do not have any rubber contacting the fuel - all the rubber fuel lines are teflon lined on the inside and they haven't used mechanical fuel pumps for a while, so the diaphragm issue is out. I just decided to use Diesel Kleen every fill up, and it also helps that the area I just moved into offers low sulfur diesel as well as #1 diesel, so I don't feel too bad if I forget to use the Diesel Kleen. It's also noteworthy that the Diesel Kleen labels on the bottle now say "improved lubrication" or something to that effect.

 

I haven't found a definate fuel leak under the hood yet but I did notice the strong smell of diesel fuel when walking around the front of the truck, indicating weak seals and a future leak. I also noticed a slight drop in fuel economy, did anyone else find this?

 

I had lost almost 2 mpg.

 

I went from 16.5 mpg average to 15 mpg average. She's so stock, it's pathetic. I hope to change that in the near future.

 

Since the switch to ULSD the rear end went out & I had a flat tire. I hate this stuff. Just not enough chemicals in the fuel anymore.
My 97 had fuel leaks when I bought it .... maybe that was in antisapation of the ULSD???? I even heard that some injectores went bad prior to ULSD. The bad fuel pumps are from the LSD we had for years.

 

The ULSD has a lot less lubricant in it. I reccomend adding some back to it at each fill up. The ULSD I think also will cause the engines not to last as long due to the lack of lubricant in diesel. And the older orings you can expect to leak now also due to the lack of lubricant. Even the farm fuel for my tractor has went ULSD and i can tell a huge difference in its power. I would really like to go back to LSD

 

I'm not certain about all this but this is what I have heard about ULSD. When you start taking sulfur out of fuel you also take out other ?aromatics/impurities? out of the fuel. These other impurities have gotten into rubber seals, gaskets, diaphragms and they swell them. As ULSD is run across or by the rubber components the ULSD "pulls out" the impurities. This in turn causes the rubber to shrink which with a little wear causes a leak. As far as lubricity or lack of from ULSD- Ive been told that after the fuel is refined I guess the oil companies put additives into the fuel to help with lubricity. Maybe someone else has heard this or knows more.