Since we are throwing in personal opinion posts, here are some more just for fun
http://www.pistonheads.com/gassing/t...momentum&mid=0
particularly:
"My 135i ran exclusively on momentum for 45,000 miles until it started going into Limp mode. I took it to the dealer and the injectors were failing on Cylinders 5 and 6."
"The base petrol for Tesco Momentum, as produced by the Greenergy company in the UK, is made from a cheaper fraction of distilled crude. In fact it's not really petrol to begin with, at the distillation phase it's a fraction known as naphtha. This isn't worth as much as refined petrol, however via reforming (specifically cracking), naphtha can be upgraded to high octane petrol. When married to a larger additives package by volume, you can iron out most of the problems with this approach.
The net result is a mostly comparable product, which is much much cheaper to produce."
* just to add, I agree there are probably better fuels than either discussed here to be had in Germany and most of the rest of Europe. Shame we cant get them here.