Has anyone tried the bolt on throttle body spacer for the 550i from aFe? It is rated at a 10 hp gain. I never believe what I read, but I would spend $150 to gain 10hp.

 

Junk, IMHO, samething as tornado crap

 

The AFE Silver Bullet Throttle Body Spacer for the 545i, 550i, 645Ci, 650i, and X5 is an excellent way to increase the horsepower and torque of your vehicle, while still improving your gas mileage. The AFE Throttle Body Spacer twists incoming air to provide a more thoroughly mixed air to fuel ratio. This provides for an increase in horsepower and torque, while improving MPG while cruising. We do have the aFe throttle body spacer in our project 135i and have noticed an increase in throttle response and overall gains as well!