How do I look after my Diesel?

[CardinalSin]

As far as which brand of diesel to use, you should use the one that has the highest CN, since the min. requirement for VAG diesels is CN51. What ever additive you use, keep in mind that you could have a tough job to get the warranty honoured, if your car would have a problem related to the fuel and the VW dealer finds out that you've used the 2 stroke oil in the fuel as an additive.

I've used 2 stroke oil in my diesels for years and have never had any fuel related problems. Just the usual positive results, quieter, smoother, better MPG and hopefully the main goal of longer lasting fuel, engine and emission components.

[gldgti]

There are enough threads about using 2SO already, fanboys quit it!

[kaanage]

Haters too?

[Ryeman]

Where do yo find the different brand CN numbers published? - I thought it was a siple case 'they all meet the legal min' of 51.

[Amalgam]

The specifications are available on the refiner's website

http://www.bp.com/content/dam/bp-cou...ate_Diesel.pdf

http://s08.static-shell.com/content/...-dieseltds.pdf

[Ryeman]

Shell state a Cetane Index of 49 for their 'Ultra Low Sulphur Diesel' fuel.
there is no mention of 'CN' - am I missing the obvious as IT is <51?!

[Ryeman]

Is there a know diesel fuel retailer that doesn't meet VW min specs?

[Amalgam]

From Wikipedia

"Cetane index calculations can not account for cetane improver additives and therefore do not measure total cetane number for additized diesel fuels. Diesel engine operation is primarily related to the actual cetane number and the cetane index is simply an estimation of the base (unadditized) cetane number."

CN and CI are not the same


Also from VeryOne | General information


Q: What type of measurement is the most appropriate for the Cetane Number?

A: Amongst the different ways to determine the Cetane Number, the Cetane Engine (ASTM D 613) is usually the standard.

Q: What is the difference between Cetane Index and Cetane Number?

A: There are 2 ways to determine the Cetane Number of a Diesel Fuel.

The first one, called Calculated Cetane Index, is a theoretical determination. It uses a calculation based on the density and the distillation range of a crude diesel fuel. This estimation is only made for fuels without any additive in it. The specification of the Cetane Index in Europe is minimum 46.

The second one, called Measured Cetane Number, uses a normalized laboratory test. The Cetane Number is determined by comparing the behavior of the tested fuel to 2 reference mixtures with known Cetane Number. In this case, all fuels, with or without additives, can be tested. The specification in Europe is minimum 51.

Cetane Improver increases the Measured Cetane Number, but has no impact on the Calculated Cetane Index.

Apparatus used for Cetane Number measurement: CFR (Cooperative Fuel Research engine, ASTM D916), IQT (Ignition Quality Tester, D6890), DCN (Derived Cetane Number, ASTM D7170) or CID 510 (Cetane Ignition Delay, ASTM D766.

Q: Why does the Cetane Index Norm differ from country to country?

A: Each country or state shall define its own diesel specification. For environmental reasons, in year 2000, Europe fixed the Cetane Index at 46, and the Cetane Number at 51, at the same time as low sulfur diesel regulation. Step by step, most of the states around the world would fix the same level of Cetane Number.

In cold weather countries, the Cetane Number can be lower during the winter season. This is explained by the difference in climate, and the addition of kerosen into the diesel. For example: the arctic diesel is at 47-49 in Europe.

[Ryeman]

So there is no specific figure that shows that one fuel is measurably better then any other?

[blameturner]

So there is no specific figure that shows that one fuel is measurably better then any other?

Apparently it's personal preference but I've heard many good reports about BP Ultimate Diesel.