[mdoyle]

It is absolutely "too good to be true", stay away from those. If you're lucky, all you'll waste is a few bucks; worst case scenario you'll ingest a fragment of it and take out a valve.

The reason these devices don't work is this- for maximum burn rate and full BTU yield, fuel needs to be atomized into the smallest droplets possible which yield the greatest surface area and best burn rate.

What these devices purport to do is to swirl the fuel/air mixture creating a faster burn but this can't occur and sustain ahead of the throttle body assembly. Any vortex formation will be canceled as it changes direction and volume and encounters obstruction.

Vortex burn rate improvement was a reality on some GM designs when it was introduced near the intake valve, but only then.

It's possible these aftermarket fins can eventually become stress fatigued from vibration and shed parts into the valvetrain because their metallurgy is unknown. Don't take that risk.