
Originally Posted by
yebo
I think you got it wrong. Sulfur actually acts as a lubricant so less sulfur equals less lubricating properties to the diesel which leads to more wear on the pump and injectors. On the other hand more sulfur equals more particulates in the exhaust, thus euro4 diesel has more smoke than euro5 diesel. "Cleanness" therefore is a measure of the sulfur content and not a measure of solid contaminants in the fuel that could cause wear on your engine components. However since philippine diesels are blended with biodiesel this lack of lubrication properties is already addressed. If you are still concerned that biodiesel does not provide enough lubrication then there are additives available.
But yes, it is better to use euro5 for the environment.
AFAIK the biodiesel blend is actually specified in the Euro5 diesel standard. It's listed as the FAME (fatty acid methl ester) content.
Sulfur as a lubricant is myth. Sulfur is not the actual lubricant, but the process of removing sulfur also breaks down certain large hydrocarbon molecules that are the ones actually adding lubrication.
On that note I'm agreed about the need to use additives. I've been using one 250ml bottle of LiquiMoly every 2500kms. The bottle says it's good for 2000kms daw but 2500km is easier to keep track of coz it ends up being two bottles ordered every oil change. I toss one in during the oil change, and the other one after 2500kms.
More on the sulfur thing here: Loss of Lubricity in Diesel Fuel
While most people may be familiar with the microbial problem (Diesel Bug) many underestimate or are unaware of the effects of loss of lubricity caused through the process of removing the sulphur.
Additionally reducing the sulphur levels in fuel decreases the acids formed in engine combustion chambers, offering the promise of extended engine oil life. So, on the face of things the reduction of sulphur is all highly positive in terms of engine wear and tear; however, there is more to it than meets the eye.
Negatives of Removing Sulphur
So if ULSD is so good for the environment and promises extended engine life why are there concerns about using it? As low sulphur emissions became mandatory, fuel refiners have had to develop new technologies to reduce the sulphur content in order to meet the emission standards. The issue is in the refining process used to remove the sulphur. The most cost effective way is to use a chemical process called hydro-processing. During hydro-processing the sulphur in the fuel is removed and replaced by hydrogen resulting in a cleaner burning fuel with improved performance. Unfortunately as hydrogen is a highly reactive element it also reacts with other components in the fuel removing the polar and aromatic compounds that provide conventional diesel fuel with adequate lubricating capability.