2018-2024 BMW X4 M40i / M40d (G02) Carbon Ceramic Brake Kit
Official Warranty: 1‑year free replacement for quality defects or coating issues under normal (non-track) use.
2018-2024 BMW X4 M40i / M40d (G02) Carbon Ceramic Brake Kit — OEM-Size Replacement
The G02 X4 M40i and M40d put SUV mass and high torque through a 348mm or 374mm front rotor package with 345mm rear rotors, so repeated hard stops can expose iron-rotor heat load, dust, and pedal consistency limits. This StopFlex OEM-size carbon-ceramic replacement kit keeps the factory brake layout while replacing the rotors, pads, hats, and floating hardware with a lower-dust, lower-mass carbon-ceramic assembly built for the exact rotor sizes listed on this page.
- Built only for 2018-2024 BMW X4 M40i / M40d G02 applications using the listed 348mm or 374mm front rotor reference and 345mm rear rotor reference.
- OEM-size replacement design retains the factory caliper position instead of converting the G02 X4 M40i/M40d to a different big-brake layout.
- Carbon-ceramic rotors reduce iron brake dust and rotating mass on a heavy, all-wheel-drive coupe-SUV that is often driven on open factory M Sport wheels.
Fitment Hard Lines
| Field | Specification |
|---|---|
| Vehicle | BMW X4 M40i / M40d (G02) |
| Model years | 2018-2024 |
| Front rotor reference | X4 M40i/M40d: 348mm, 374mm |
| Rear rotor reference | X4 M40i/M40d: 345mm |
| Page type | OEM-size carbon ceramic replacement |
| Minimum wheel size | 18" (for the 348 mm rotor) |
For OEM replacement orders, StopFlex builds around the factory rotor specification shown for this vehicle. Front floating-caliper setups require manual review before production. If the car uses aftermarket calipers such as Brembo, AP Racing, Alcon, or Wilwood, the order can still be built, but the exact caliper model, pad shape, and rotor dimensions must be confirmed before production.
This setup uses a 348 mm rotor, so the minimum wheel size is 18". Wheels under 18" will not clear the caliper and rotor, and spoke profile and offset affect clearance too — confirm your exact wheels before ordering.
Why StopFlex CCB
Lower Unsprung Mass
StopFlex carbon-ceramic rotors are engineered to reduce rotor mass versus comparable iron discs, helping the suspension react cleaner and the steering feel more precise.
High-Temperature Stability
The carbon-silicon-carbide matrix is built for stable braking behavior at temperatures that can push iron rotors into heavy fade.
Rust-Free Rotor Surface
Carbon ceramic does not form orange flash rust after rain, washing, or storage, keeping the visible rotor face cleaner behind open wheels.
Long Street-Service Potential
In normal road use with matched pads and proper bedding, StopFlex CCB rotors are designed for far longer service life than typical iron replacement rotors.
Low Visible Dust
When paired with matched StopFlex pads, the system produces very low visible brake dust compared with conventional iron rotor and pad combinations.
Premium Ceramic-Glaze Appearance
StopFlex's proprietary coating creates a bright, high-end ceramic-glaze finish with subtle glaze texture and a more premium visual character behind open wheels.
Street-Usable Cold Bite
Street Spec and Track-Day Spec rotors are designed for normal first-stop road use, including cold-weather operation. Motorsport Spec is the competition-focused exception.
Continuous Fiber Reinforcement
Long-fiber carbon ceramic construction improves structural strength and thermal durability versus chopped-fiber approaches.
Custom Rotor Hat Color
Every StopFlex OEM replacement order can be built with a custom rotor hat color, giving the carbon ceramic rotor package a cleaner match with the wheel, body color, and overall build style.
Heat Management Note
Carbon ceramic rotors tolerate extreme surface temperature, but they do not remove every heat-management requirement. During repeated hard stops, heat can still soak into pads, fluid, seals, calipers, wheels, and nearby components. For long track sessions, mountain descents, or sustained aggressive driving, brake cooling and high-temperature fluid are still recommended.
Street / Track-Day / Motorsport Rotor Options
Street Spec
Ceramic coating, cross-drilled face, and large cooling channels.
Best for daily driving and premium street builds that need clean cold bite, low dust, corrosion-free appearance, and long service life.
Track-Day Spec
Ceramic coating, blank face, and honeycomb cooling channels.
Best for fast-road and track-day use where repeated braking stability matters more than maximum visual drilling style.
Motorsport Spec
Uncoated blank face with honeycomb cooling channels.
Best for race-focused builds that run competition pads, high-temperature fluid, cooling strategy, and a proper warm-up window. Not the default street choice.
Package Scope
| Item | Details |
|---|---|
| CCB rotors | Full-car set by default |
| CCB brake pads | Matched for StopFlex carbon ceramic rotors |
| 7075 aluminum floating rotor hats | Vehicle-specific fitment |
| Stainless floating hardware | Full-car hardware set |
| Rotor hat color | Custom rotor hat colors are available for every OEM replacement order. |
| Order scope | Default listing is full-car set. Front-only or rear-only orders can be arranged after confirmation. |
FAQ
Will this kit fit every 2018-2024 BMW X4 G02?
No. This page is limited to the BMW X4 M40i and M40d G02 trim family with the exact rotor references listed here: 348mm or 374mm front and 345mm rear. Do not order it for xDrive30i, X4 M, or any car with a different brake package.
Do I need to change calipers or parking brake parts?
This is an OEM-size replacement kit, so it is designed around the factory G02 X4 M40i/M40d caliper layout. The rear brake package is intended to retain the factory electronic parking brake, auto-hold function, and rear caliper architecture when the vehicle matches the listed 345mm rear rotor setup.
Why switch from the factory iron rotors on an X4 M40i or M40d?
The carbon-ceramic rotors target the main drawbacks of the stock iron setup on this heavy performance SUV: heat accumulation during repeated braking, visible gray dust on open wheels, and rotating mass at each corner. The kit also includes matched pads, hats, and floating hardware rather than mixing carbon-ceramic discs with unknown pad compounds.
What should I confirm before ordering?
Confirm the vehicle is a G02 X4 M40i or M40d, verify the front rotor size on the car is one of the listed references, confirm the rear rotor is 345mm, and check wheel barrel clearance if the wheels are aftermarket. StopFlex should review VIN, rotor diameter, and wheel details before shipment when there is any uncertainty.
Need Fitment Confirmation?
Send the exact vehicle details, current rotor sizes, and caliper type before ordering.
More Contact Information
We’re here to help! Whether you need expert advice on brake setups, have questions about your order, or just want to share feedback, our team is ready to assist you. Reach out via your preferred channel below, or use the inquiry form.
Get in Touch
Business Hours
Monday – Saturday, 9:30 AM – 6:30 PM (GMT +8)
Current Time:
Follow Us
- Choosing a selection results in a full page refresh.