Shell V-Power Diesel is a premium fuel that has additional additives designed to promote engine longevity, reduce engine deposits and subsequently improve performance and economy. There is no independent testing to support its benefits, but anecdotally some owners find that their vehicles run better on this fuel. There are no price controls on UK petrol stations, other than the fact that in areas where there are a number of different retailers, anyone charging extortionate rates is likely to see a decline in footfall. As with premium fuels, there is very little independent testing around diesel additives, but again some owners have experienced good results. It is all a matter of what you are prepared to pay and if you feel that V-Power diesel is too expensive then a standard diesel and a fuel additive may be a suitable alternative.