Off-Road versus Road Fuel

[Ragbagger]

On our trip to see the last Shuttle launch, any excuse for a boat trip, we fueled at New Smyrna Beach. The marina there sold on-road deisel. He has a tanker truck he fills and hooks up to the fuel system. The system worked fine although a little slow.

We paid .10 less than the off-road at our home port, St Simons Island, GA.
The engines ran better, had more power, ran 10 degrees cooler, and most importantly, didn't soot up the transom. If we could go somewhere around here and get it, we would.

Now I have seen the benifits of on-road diesel, I wonder the wisdom of using low-grade "Shrimp Boat Fuel" in high performance diesel engines. I have the 6-71 TIA's @ 465 hp. It gooks up the filters too.

Should we discontinue this use of high sulpher fuel for performance reasons?

 

[REBrueckner]

Some good insights provided here:

http://www.samsmarine.com/forums/showthread.php?t=11038&highlight=road+diesel

If you can find a dock or pier that will let you have a truck delivery you boat, you can try that....but fines for spills and regulations including coloring of off road diesel fuel make that an iffy business in many states these days.

 

[Boatsb]

What makes you think it's the on road Vs the off road? The difference is the tax is or is not paid. Your home marina may be buying cheap fuel but I get off road diesel at my marina and it has always been fine. Others who have passed by and filled up seemed to think so too. I get no soot and have a pretty clean burning 1966 8V53 naturally aspirated engine with plenty of life in it.

See if the marina you usually use goes through a lot of fuel or is it old and stale. Maybe they have a problem with their tanks.

 

[rsmith]

off road should be way cheaper since you dont have the road taxes. I wonder if the red dye makes smoke?

 

[eze2bme]

I also have my fuel truck deliver off-road diesel ... never been a problem and no transom soot either ... and usually $.33 less than highway diesel.

 

[captddis]

I noticed a big difference in smoke when I had the Cats. The on road was definately cleaner. Pier 66 used to sell both fuels as the mega yachts liked the undyed fuel for cleaner operation.

 

[SKYCHENEY]

All on-road fuel is now ultra-low sulfur. The off-road fuel is now in the process of switch over and could be either low sulfer 500ppm or ultra-low sulfur 50ppm. Maybe that is the difference.

 

[Scotte28516]

I own a trucking company. The only difference between on road diesel and off road diesel is the road use taxes and the addition of red dye to the off road diesel. On road goes in the tractors tanks, and red dyed off road goes into the reefer units. The red dye has zero effect on smoking/soot nor engine performance. Nationwide there are roadside random "truck inspections" where the Feds will dip the fuel tanks of tractors to check for the prescence of red dye. If there is, federal offense with a huge fine! The only difference with diesel fuel for on road use is either standard #2 dlesel or in extremely cold winter climates, #1 diesel("winter blend") which has anti-gelling agents added and sometimes a bit higher cetane rating.

 

[Ragbagger]

There may be different grades of off-road diesel. There is obiviously a big difference between the off-road I have been purchasing and the on-road fuel as evidenced by the engine performace. I am going to discuss it with the marina management. Most of the power boats in my marina have what I would catagorize as high-performance diesels and would see the same benifit as we saw when using the on-road fuel. Our marina is a well managed operation, but I am concerned about their fuel quality.

 

[captddis]

I own a trucking company. The only difference between on road diesel and off road diesel is the road use taxes and the addition of red dye to the off road diesel. On road goes in the tractors tanks, and red dyed off road goes into the reefer units. The red dye has zero effect on smoking/soot nor engine performance. Nationwide there are roadside random "truck inspections" where the Feds will dip the fuel tanks of tractors to check for the prescence of red dye. If there is, federal offense with a huge fine! The only difference with diesel fuel for on road use is either standard #2 dlesel or in extremely cold winter climates, #1 diesel("winter blend") which has anti-gelling agents added and sometimes a bit higher cetane rating.

All I can say is the transom stayed clean with the undyed fuel and when I would service my Racors, I would fill them with on road diesel from the gas station. Start the engines and clean exhaust, watch the filters fill up with red diesel and along came the smoke. This was with 3208TA's. I have never noticed a difference with the Detroits.

 

[GJH]

Where are you buying your fuel near St. Simons? A marina or Ocean Petroleum?

 

[Ragbagger]

We fuel at our local marina. Morning Star-Golden Isles

 

[Boatsb]

On road diesel can NOT HAVE any of the contaminants that are "legal" in off road fuel. They may be getting a less refined grade in some places.