There was a test in Russia of 14 different octan boosters.

They checked how octan boosters influence on octan number.

so here is a list of boosters:

1. ABRO (USA) octan gain +0.5
2. GUNK (USA) octan number decreased <span style="color:red">-0.2</span>
3. Hi-Gear (USA) no effect 0
4. Kerry (Russia) +0.1
5. NOS (USA) octan decreased on <span style="color:red">-0.2</span>
6. NST (Russia) gain +0.2
7. Quaker state 4x4 (USA) octan gain is +0.7
8. SCT (Germany) <span style="color:red">-0.3</span>.
9. SNAP (USA) +0.4
10. Step Up (USA)<span style="color:red">-0.5</span>
11. STP (USA) +0.4
12. Rubikon (Russia) no effect 0
13. Sonax (Germany) <span style="color:red">-0.1</span>
14. Wynn’s. (Belgium) the best booster!!! +1.5

For russian speaking members here is the link to the article:
http://www.zr.ru/show_arch.pl?ida=44596

 

I have been using Turbo 108 since my first car, 89 Hyundai Excel. I can honestly say I felt the difference after using that product.