5 to 20HP? Sure.
If you combine this to the recently advertized Tornado gizmo, a few bottle of ProLong additive, 6 Tritanium Super spark Plugs, a couple of bottle of octane boster into Premium gasoline and a chromed exhaust pipe, that would turn my 260E into an E55 beater.
I'll have 2 please.
Keep your money for a few good books on performance improvements.