I have used Techron when I have suspected a build up of deposits on injectors, and it has resulted in smoother running. I have used it rarely, as I much prefer to buy better quality fuels and not overdose with it from the bottle.

I wouldn't ever use Lucas, Lubro-Moly, or other fuel additives, other than diesel fuel stabilizer. Read the data sheets, and see that they are usually made up of kerosene, or white camping (Coleman) fuel, and not much more.

I don't worry much about ethanol, since I am able to largely avoid it by purchasing select premium fuels. But I don't worry about 5% ethanol much in any case.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue