So far, na try ko pa lang na additive is Liquiy moly... the MoS2 and the ceratec...

The MoS2 which has lots of moly in it did improve my fuel consumption from 4-5 to 5-6 on a 6 cylinder gasoline engine.
while the ceratec which has lots of boron performed just the same from 10-11 to 11-12 on a 4 cylinder diesel engine.

i think before you use any additive it must have proper documentation and technical specs in the first place so you can benchmark it...