so far i've noticed a 50% increase...but the last time i had my pcv jar apart i noticed the zinc coated BB's were starting to rust...so i dont think its doing so well right now...i need to get me some silica gel. the hydroboost seems to be working real well right now...its been two fillups and it still seems to be working, but i will take it apart soon to see how far gone the electrodes are...if everything is working u should see a 50-70% increase at least...since it works with the manifold vacuum it will work best at cruise or whenever manifold vacuum is highest...if u like to accelerate and deccelerate at speeds higher than 40 mph then that wont be very effective, i heard 0-40mph and cruise is where manifold vacuum is highest...but i could be wrong. i think a pump would work better, but the only problem is that they arent reliable since they are being run dry and could burn out or die anytime.
