Drag reduction clips save gas

What are drag reduction clips and how do they save gas?

Drag reduction clips or spreader springs are wire springs that exert slight outward pressure on the brake pads to move them slightly away from the brake rotor every time you release the brake pedal. In disc brake systems without drag reduction clips, the brake pads are designed to move slightly when the pedal is released due to the very small retraction of the caliper piston caused by the square cut O-ring roll-back.

In real-world driving conditions, the caliper piston roll-back is often not enough to move the pads away from the rotor, so the brake pads often remain in contact with the brake rotor, causing a slight drag as you take off from a stop.

Slight irregularities in the rotor face contact the brake pads and cause them to move back as you pick up speed. This “knock-back” is what normally forces the pads away from the rotor when driving.

In addition to knock-back, the Bernoulli Effect also pushes the brake pads away from the rotor. The Bernuoulli principle holds that as the rotor spins and move air, the air exerts outward pressure on the brake pads.

Bernoulli effect on brake pads

You experience the Bernoulii effect after driving for long periods at highway speeds. The first time you apply the brakes after a long drive, you notice that it take more brake pedal travel to apply the brakes. That’s because the brake pads have been pushed farther away from the brake rotor due to the air flow pressure.

Drag reduction clips increase both gas mileage and brake pad life

By using spring force to move the brake pads away from the rotor on brake release, there’s less brake drag and thus less brake pad wear.

Drag reduction clips are standard equipment on new cars

Most car makers have begun installing these spreader springs at the factory to increase gas mileage standards. If your vehicle came with drag reduction clips, you should install new clips when performing a brake job. The old clips lose tension due to heat cycles.

Retrofit spreader springs

You can also retrofit your older vehicle with drag reduction clips. Simply buy a set designed for your vehicle and install them when you install new brake pads

©, 2020 Rick Muscoplat