# Dinan 19-25 BMW X4 M40i Freeflow Axleback Exhaust System - Polished

While looks are important, the auditory advantages are what any enthusiast is truly after with an exhaust system, and the Dinan offering for the G01/G02 M40i platform delivers in spades. For not only aural enhancement via the elimination of the central collector/resonator, but also weight savings and simplicity. The stock single-to-dual pipe setup has been abandoned in favor of an enlarged, straight, unrestricted, and freer flowing single pipe system. This pathway feeds into a Helmholtz equipped muffler that limits frequencies associated with drone, as well as assists in altering the overall tone of the setup to deliver the signature low Dinan rumble. The no-nonsense design allows versatility in volume levels with the retained factory valve functionality. Go from refined when cruising (low RPM’s) to rowdy when in it (high RPM’s), with ease. Or better yet, pair the system with an exhaust valve remote and have full control of elevating or reducing the sound! When open, the system behaves as a straight pipe solution that promotes maximum flow and volume for an exhilarating and forceful chorus. When the valve is closed however, exhaust gases are wholly redirected through the muffler and emit more tempered vocals acceptable for even the most sensitive ears. It is the perfect blend of civility when cruising or the full spectrum of auditory delight when in the throttle. No matter the situation, the Dinan valved cat-back exhaust system is the answer for the discerning enthusiast looking for sound without sacrifice.

-   Quad 3.75-inch (95mm) double-walled, polished (or black ceramic coated) clamp-on tips with laser engraved Dinan logo
-   Factory-like fitment with included mounting hardware and valve componentry for both pre-LCI and LCI compatibility
-   Factory valve functionality retained; refined or rowdy from the same exhaust
-   7-pounds lighter than the stock system (60-pounds vs. Dinan: 53-pounds)
-   Enjoyably louder, sportier sound w/ a delightful octave drop
-   Drone abatement technologies used to reduce cabin resonance
-   Larger diameter piping for increased flow (83mm vs. 80mm)
-   Factory resonator/collector removed for increased volume
-   Direct bolt-on w/ no cutting or welding required
-   Maximum gains of +6 HP and +5 lb-ft of torque
-   100% 304 Stainless Steel construction

This Part Fits:

Year

Make

Model

Submodel

2018-2024

BMW

X3

M40i

2019-2025

BMW

X4

M40i

## Details

- **Price:** 2959.52 CAD
- **Vendor:** Dinan
- **Type:** Axle Back

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 2959.52 CAD | In stock |

## Images

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- Photo - out of package
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> Source: [Standard Auto Part](https://www.standardautopart.com/products/dinan-19-25-bmw-x4-m40i-freeflow-axleback-exhaust-system-polished)
> Updated: 2026-07-05