A brake kit needs to clear your wheel, work with your parking brake, and — if your suspension isn't stock — reach far enough to do its job. Here's what to check before you order.
Do you need a wheel spacer?
A bigger caliper takes up more room inside the wheel than your factory brakes did. On some vehicles — usually compact and mid-size cars with tighter wheel wells — the new caliper sits close enough to the wheel spokes that a spacer is needed to push the wheel outward and restore clearance. This depends on your wheel's spoke design and offset, not just its diameter, so two 18-inch wheels from different manufacturers can behave differently on the same kit.
TEI wheel spacers are forged aluminum, carry a 1-year warranty, and are sized to the smallest increment that solves the clearance issue for your specific vehicle and wheel. Typical passenger-car spacers run 15–20mm per side; a few applications need more — see the vehicle-specific notes below for real examples (25mm and 30mm cases).
It's also common for the front of a kit to clear without a spacer while the rear needs one. On EPB-equipped cars the rear caliper's motor has to clear the control arm or strut, so the rear bell is often built shallower than the front — that's the usual reason the two ends of the same kit behave differently.
As a rough starting point by badge — always confirm against the clearance table below or with our team, since this varies by model and wheel:
- BMW, Mercedes-Benz, Audi generally clear without a spacer, except: BMW 1-Series, 2-Series, X1, X2; Audi A1, A3, Q1, Q2, Q3; Mercedes A-Class, B-Class — these need one. The BMW 2-Series (F44) doesn't clear even our smallest 18" kit (P60EV).
- Japanese brands (Honda, Toyota, Mazda, Nissan, Subaru) generally need a spacer.
- Korean brands (Hyundai, Kia) generally need a spacer — including some EVs, where the OEM bell is shallow.
Find your kit to see whether your combination needs one, or send us your wheel specs for a manual check.
Minimum wheel clearance by caliper family
Every TEI caliper-and-disc combination has a minimum wheel inner diameter it needs to clear the caliper without touching the spokes. We build in a 10mm safety margin above that bare minimum wherever possible; 6mm of clearance is the absolute minimum we'll work with. The table below lists the bare-minimum wheel inner diameter and caliper ET (reach) dimension for each caliper family and disc size — check the spec sheet on the specific product page for your kit, or see our Tech Docs for how we measure it.
| Caliper | Disc spec (mm) | Min. wheel inner diameter (mm) | Caliper ET (mm) |
|---|---|---|---|
| S-X10 | 400x36 | 473 | 81.7 |
| 410x36 | 478 | 81.7 | |
| 420x36 | 482 | 81.7 | |
| 440x36 | 493 | 81.7 | |
| SR10 | 400x36 | 468 | 84 |
| 410x36 | 478 | 84 | |
| 420x36 | 485 | 84 | |
| 440x36 | 502 | 84 | |
| SR8 | 378x32 | 439 | 82 |
| 400x36 | 458 | 82 | |
| 410x36 | 468 | 82 | |
| 420x36 | 477 | 82 | |
| S60-PLUS | 378x32 | 436 | 82.5 |
| 400x36 | 459 | 82.5 | |
| 405x34 | 463 | 82.5 | |
| 410x36 | 469 | 82.5 | |
| 420x36 | 480 | 82.5 | |
| P60EV | 330x28 | 391 | 63 |
| 345x28 | 399 | 63 | |
| 355x28 | 409 | 63 | |
| 380x28 | 434 | 63 | |
| P60EV+ | 355x28 | 409 | 64.5 |
| 380x28 | 434 | 64.5 | |
| P60NS | 355x32 | 413 | 78.5 |
| 378x32 | 436 | 78.5 | |
| 400x36 | 458 | 78.5 | |
| P60NS+ | 355x32 | 413 | 76.5 |
| 378x32 | 436 | 76.5 | |
| 400x36 | 458 | 76.5 | |
| P4-EXPLORE (Front / Rear) | 330x28 | Front 378 / Rear 398 | 73 |
| 345x28 | Front 392 / Rear 412 | 73 | |
| 355x28 | Front 402 / Rear 422 | 73 | |
| 380x28 | Front 428 / Rear 448 | 73 | |
| T665 / T683 (SR6) | 332x32 | 388 | 75 |
| 355x32 | 405 | 75 | |
| P40NS | 300x24 | 357 | 71.9 |
| 330x28 | 382 | 71.9 | |
| 355x28 | 406 | 71.9 | |
| P40NS+ | 330x28 | 376 | 72 |
| 345x28 | 391 | 72 | |
| 355x28 | 400 | 72 | |
| P60ES | 355x32 | 404 | 74.6 |
| 378x32 | 425 | 74.6 | |
| SR4-EXPLORE (Front / Rear) | 330x28 | Front 386 / Rear 397 | 73 |
| 355x28 | Front 409 / Rear 419 | 73 | |
| 380x28 | Front 434 / Rear 445 | 73 | |
| 400x28 | Front 441 / Rear 468 | 73 | |
| 410x28 | Front 457 / Rear 476 | 73 | |
| P4+EXPLORE (Front / Rear) | 330x28 | Front 386 / Rear 397 | 74 |
| 355x28 | Front 401 / Rear 420 | 74 | |
| 380x28 | Front 424 / Rear 444 | 74 | |
| 400x28 | Front 446 / Rear 466 | 74 | |
| 410x28 | Front 455 / Rear 475 | 74 | |
| P40NS-R | 330x28 | 386 | 70 |
| 345x28 | 393 | 70 | |
| 355x28 | 401 | 70 | |
| 380x28 | 427 | 70 | |
| 400x28 | 447 | 70 | |
| P42-SUPER | 286x24 | 341 | 63.5 |
| 296x24 | 346 | 63.5 | |
| 290x24 | 340 | 63.5 | |
| 330x24 | 348 | 63.5 | |
| P40EV | 330x28 | 377 | 64.5 |
| 345x28 | 391 | 64.5 | |
| 355x28 | 401 | 64.5 | |
| TEI Electric Secondary Caliper | 330x28 | 392 | — |
| 355x28 | 419 | — | |
| 380x28 | 438 | — | |
| 400x28 | 460 | — | |
| Cable-Actuated Secondary Caliper | 355x28 | 405 | — |
| 380x28 | 432 | — | |
| GTS4 / GTS4-R | 330x28 | 380 | 78 |
| 345x28 | 392 | 78 | |
| 355x28 | 401 | 78 | |
| GTS-6 | 332x32 | 393 | 86.5 |
| 355x32 | 406 | 86.5 | |
| 378x35.6 | 422 | 86.5 | |
| 380x34 | 425 | 86.5 | |
| GTS6-N | 332x32 | 393 | 86.5 |
| G45-R V97 | 355x28 | 402 | —† |
| TA60 (G61) / TA661 | 354x28 | 405 | 75 |
| TA41 (G42) | 365x28 | 410 | 70.1 |
| TA41-P (G43) | 345* | 393 | — |
| GT40-MONO | 286x24 | 343 | 71.3 |
| 296x24 | 350 | 71.3 | |
| 330x28 | 373 | 71.3 | |
| GT60-MONO | 355x32 | 414 | 106.5 |
| 378x35.6 | 428 | 106.5 | |
| 380x36 | 429 | 106.5 | |
| 390x36 | 437 | 106.5 |
— = ET dimension not published for this caliper (typically our secondary/parking-brake calipers). * TA41-P (G43): disc diameter only — thickness isn't recorded for this variant in our records. † G45-R V97: fitment on deep-dish wheels depends on wheel X-distance rather than a standard ET figure — contact us to confirm.
Vehicle-specific fitment notes
A handful of platforms have quirks that don't show up in a generic clearance table. If your vehicle is listed below, read this before ordering:
| Vehicle | What to know |
|---|---|
| Honda Civic / Integra / GAC Yingbao (Shadow Leopard), front | 17–18" aftermarket wheels: 324mm disc only. 10th/11th-gen Civic and Integra on 17" wheels (OEM or aftermarket): dual-caliper kit only — the EPB motor contacts the OEM strut and OEM wheel clearance isn't enough to push the caliper outward. OEM wheels need a 25mm spacer; aftermarket wheels still protrude too far to look right. |
| Honda (other models), OEM 18" wheels | P4-EXPLORE with a 355mm disc isn't recommended — inner clearance is insufficient. |
| Audi A6L, rear | Confirm the rear suspension strut type first. Air-suspension (air bag) models require a dual-caliper setup. |
| XPeng X9, rear | OEM wheels: dual-caliper only — the electro-mechanical caliper would need the bell pushed outward by a 30mm spacer and still lacks clearance. Aftermarket rear wheels: SR4-EXPLORE is worth considering (confirm your wheel specs with us first). |
| Volkswagen & Skoda | Some special models require a front knuckle replacement. Confirm your model year and engine (naturally aspirated or turbocharged) before ordering. |
| BMW 3-Series / 5-Series with EPB, OEM 18" wheels | Can't fit a 355×22mm larger disc — the OEM caliper sits too high for the available wheel inner clearance. Aftermarket 18" wheels aren't recommended for a larger rear disc either. |
| Foot-brake / mechanical-drum parking brake models (e.g. BMW 3-Series F-chassis, older Toyota Reiz / Highlander) | The rear uses a parking-brake drum built into the disc hat, so a larger-disc upgrade isn't supported there — we spec P40NS-R for these, which generally clears OEM wheels. |
| Changan UNI-V, rear | OEM 19" wheels don't clear a 355×12mm larger disc — the OEM caliper's brake-line fitting interferes with the wheel. 330×10mm is the largest disc that fits on OEM wheels. |
| GAC Yingbao (Shadow Leopard), rear | Larger disc capped at 324mm, dual-caliper kit only — there's no electro-mechanical caliper option for this application. OEM and aftermarket wheels both lack clearance for anything bigger, so this is a hard limit regardless of wheel choice. |
| BMW 3-Series, OEM 18" wheels | A 343×22mm larger disc needs the OEM caliper ground for clearance. Aftermarket wheels: depends on the specific wheel style. |
| Great Wall GaoShan 8/9, rear | Dual-caliper kit required — the electro-mechanical caliper motor contacts the rear tie rod/control arm. OEM wheels clear without issue. |
Contact our team if your vehicle isn't listed — most fitment questions come down to a quick check against your exact model and wheel.
Electronic parking brake (EPB) vs. mechanical parking brake
A traditional parking brake is mechanical: a hand lever or foot pedal pulls a cable that clamps the rear brakes directly. An electronic parking brake (EPB) replaces that cable with a small electric motor — usually built into the rear caliper — that clamps and releases at the press of a switch, often labeled "P," near the shifter.
To check which one your car has:
- A physical hand lever or foot pedal means a mechanical parking brake.
- A small electronic switch instead of a lever means EPB.
- Your owner's manual will state the parking brake type directly.
This matters for kit selection because the two systems aren't interchangeable at the caliper. A rear kit built for a mechanical parking brake has nowhere for an EPB motor to connect, and swapping an EPB vehicle's rear caliper for the wrong kit can disable the parking brake entirely. If your car has EPB, the replacement rear caliper has to house its own motor — that's our electric secondary caliper, not a standard rear kit — and if your car uses a cable-actuated parking brake instead, it takes our cable-actuated secondary caliper (see the clearance table above for both). EPB only controls the rear wheels, so a front-only brake upgrade never touches it either way.
Mechanical parking brake systems vary too: some cars build the parking brake into a small drum inside the rear disc hat, which caps how large a disc you can fit there (see the Foot-brake / mechanical-drum row above); others run the parking brake through the cable-actuated caliper itself, where a handful of models (e.g. Ford Mustang, older Ford Explorer) use a small dedicated cable-parking-brake caliper alongside a dual-caliper kit to keep both the brake upgrade and the parking brake working.
Find your kit or tell us your vehicle, and we'll confirm the correct rear kit for your parking brake system before you order.
Lifted or off-road suspension
If your vehicle has been lifted or widened — including portal-axle off-road builds — or runs long-travel off-road suspension, the standard-length brake line may no longer reach — increased ride height and suspension travel add distance between the frame and the caliper. In these cases a longer stainless-braided line is needed so the line isn't over-stretched at full droop. Let us know if your vehicle is lifted when you order so we can confirm the correct line length.
Two symptoms to watch for after fitting a line: if it rubs against something, that's usually a routing issue or the line is too long; if a fitting cracks, check whether the line stretches tight at full steering lock — that means it's too short and you need the next size up.
Still not sure?
Fitment is specific to your exact vehicle, wheel, and suspension setup. Find your kit for an instant check, or contact our team with your vehicle details, wheel size, and a photo of your current caliper — we'll confirm before you order.
What information should I send for a manual fitment check?
Send your vehicle year, make and model, VIN if available, wheel diameter and width, offset or ET, parking-brake type, and any wheel, suspension or body modifications. Photos of the wheel spokes, inner barrel and current caliper are especially useful. A wheel can have enough diameter but still lack spoke clearance, so the exact wheel specification matters.
What to check after installation
Before driving normally, confirm that the wheel rotates freely, the caliper and brake line do not contact the wheel or suspension, all fasteners are installed as specified, and the brake pedal feels firm. Follow the supplied installation and bedding-in instructions. If anything contacts, leaks, feels abnormal or triggers a warning light, stop and have the installation inspected by a qualified brake technician.
Fitment reference guide
