Just some stuff I got to reading after reading this thread - hope you find it of interest
http://www.tyresmoke.net/forum/tyresmoke-reviews/68125-bp-ultimate-diesel-10k-review.html
Shell V-Power Diesel
V-Power Diesel is Shell's version of an enhanced diesel fuel, similar, say to BPs 'Ultimate Diesel'. Like BP Ultimate Diesel, Shell V-Power Diesel is designed for modern compression-ignition diesel engines, to facilitate enhanced engine performance along with increased engine protection, for more consistent operation and engine longevity.[5]
V-Power Diesel is a blend of regular petroleum-based diesel and synthetic diesel, created using gas to liquids (GTL), along with some extra additives designed to clean the injection system and improve injection pump and injector lubricity.
One characteristic of V-Power diesel is that it is a lot clearer and odourless than normal diesel, mainly due to the synthetic GTL component.
The fuel is slightly less dense than regular diesel so, per volume, the unit energy is actually lower than regular diesel. This is offset, as the fuel tends to ignite more readily (and thus has a higher cetane rating) than regular diesel, and a side benefit of this is that it tends to produce less soot during combustion.
Anecdotal evidence shows that its performance varies depending on how an engine is set up. In most cases, it will make a rough-sounding engine run noticeably smoother, and can also alter the performance characteristics; typically some low-end torque is lost, but performance in the middle of the rev range and above is increased. In some engines however, particularly well-tuned common rail turbodiesels, very little effect can be seen or felt.[citation needed]
Although the former is true for the European market, Shell also markets a different "premium" diesel in Canada, which they state "Is specially formulated for year-round Canadian weather conditions, with a cetane improver, a de-icer and a corrosion inhibitor."[6] but Shell also states that V-Power diesel will typically have an increased cetane rating of 1 to 2 points over standard diesel, which meets Transport Canada's minimum mandated rating of 40.[7] It also contains no GTL components at all.