muzzimbidgie replied:

Yes, it's been available in perth for some time. I don't know if it's the 50 ppm stuff, but BP are advertising it as ULSD Ultra Low Sulphur Diesel. My mechanic recons it's the way to go.

I met another mechanic at a wedding a while back and he went on and on about it stuffing up older style diesels by causing wear in the fuel pump and valves.

According to him, the sulphur acts as a lubricant, and similar to old style petrol engines, which rely on the sulphur to lubricate the valves, the new fuel doesn't offer as much lubricity as it did before.

The new "hi tech" diesels, like the 3.0 patrol etc; are built to run on this new stuff.

I have read other posts on here, and as always, you get ten different answers from ten different people, but I don't recall anyone being able to prove or disprove the above. So I guess only time will tell.

Member - Captain (WA) replied:

Hi SantaAus,

This issue has been raised before, below is a cut and paste from my previous response in thread 14221.

Not only is low sulphur better for the enviroment, its better for your engine! Advantages of low sulphur diesel, apart from cleaner exhaust emissions, include reduced corrosion on pistons/rings/bore, reduced contamination of oil and improved storage life of diesel. Note that sulphur itself is NOT a lubricant.

The corrosion improvement occurs as previously the sulphur reacted with the water (combustion by-product) and produced sulphuric acid. This acid aggressively attacks metals as well as contaminating the oil.

The seal problem is supposedly related to "BUNA-N" and Nitrile seals and is potentially a problem for older rotary injection pumps. In-line injection pumps are not affected as they do not have these seals in contact with the fuel.

Apparently the sulphur in diesel causes the seals to swell and switching to low sulphur causes the seal to shrink, cracking it. BUNA-N seals that have always used low sulphur fuel apparently are not affected.

The lubrication issue is caused by the process to used remove the sulphur, as it removes other components that aid lubrication. But refiners are aware of this now and add a lubricant during processing.

Western Australia has had low sulphur diesel since 1/1/2000, when it dropped from 1300ppm to 500ppm. While its a significant (~60%) drop, sulphur is NOT totally removed from the fuel. As of 31/12/2002 it is ILLEGAL to sell diesel in Australia containing more than 500ppm sulphur. Some refiners (BP/Shell) offer ultra low sulphur fuel with only 50ppm, but lubricity is maintained with additives.

Many diesel engines used in Europe previously could not be used in Australia because of our "dirty" diesel. The new regs bring us into line worldwide and will enable more high performance diesels to be used in Australia.

The only "losers" with low sulphur diesel were the early users when the lubrication issues were not well known, along with older rotatry fuel pumps with the older type seals.

I hope this clears up a few misconceptions.

Cheers

Captain

3.0turbob replied:

My brother is a tanker driver for Mobil. I have asked him about this before and he tells me that ALL the fuel companies, BP, Caltex, Shell etc tankers are filled from the same dispenser at the refinery @ Kurnel (Sydney). So if BP say they have low sulpher diesel, I'd say they all have it.

SantaAus replied:

I am pritty sure that i know the answer to this, but anyway. I just had my fuel injection system overhualed, which means that the seals will be able to cope with the 50ppm diesel?

Thanks
SantaAus