I have one on a Hyper .21m and I noticed a difference in the bottom end. I went and ran the car without it and got it tuned in and the normal race stuff. Let the engine come in and cool after putting a few tanks through it. Then I put the bottle on and set the engine again. I noticed a difference. It's really not alot but for a $5 piece that actually comes in a few engines, built in, it's not really a worry.