ok here is a mini-nf ultra review.
the method i used to add the nf ultra was fill the tank half way, add the nf and then fill up to first click. i figured this would be a fairly good way of mixing the nf with the fuel.
didnt take long for the car to boost an extra 2 psi. my 135i was now stupidly fast. relentless acceleration and breaking traction in the first 3 gears in the dry. unbelieveable difference.
just below half way on the tank, the car didnt seem to boost as much. i used the same testing parameters - car warmed up but not hot. weather was cool as it was the day before.
when the tank was nearing the end, the car started its trouble. engine shuddering like crazy with no power but also no error light. i later plugged my bavarian technic cable in and the code indicated misfire in cylinder 5. hasn't done it pre or post nf.
so if you asked me the question, would you recommend nf ultra? My answer at different stages would be:
for the first half of the tank, i would have said, most definitely yes. i dont ever want to be without it in my car. the difference in performance was like going from stock to jb4.
for the second half of the tank, i would say, not really, didnt notice much difference to jb4 and no ob.
for the last bit of the tank just before the low fuel light warning comes on, i would say most definitely not. my car felt broken. i remember at the time thinking about moranor's tow truck thread.
now the problem i experienced could be a mixing issue or maybe even something totally unrelated to the ob. whatever the cause, i would be nervous to use ob again. this may be unfair on octane boosters but one bad experience whether related or not is enough to scare me away. my suggestion to those who want to use ob is to give it a try and see if it works for you. it works for lots of members on this forum. my car had a love/hate relationship with it.