BMW M135i F40: the complete exhaust system guide
The M135i F40 switched to 4 cylinders and all-wheel drive: 306 hp that works in all weathers. The B48 in its most muscular form has plenty of punch, but its factory sound is anonymous. Our exhaust gives it character and crisp crackles, with discretion preserved when the valves are closed. Here you will find everything that matters before configuring the exhaust for your BMW M135i B48 F40: material, valves, tips and vehicle inspection.
Written by ROG Motorsport · Updated

Your ROG exhaust for the BMW M135i B48 F40
From €2,490 in stainless steel, €2,990 in titanium
Configure my exhaust- Vehicles
- BMW M135i B48 F40
- Engine
- B48 · 306 hp · 450 Nm
- Exhaust
- Valved cat-back, built for your VIN
- Material
- 304 stainless steel or titanium
- Valves
- ROG remote, or factory control if your vehicle has it
- Lead time
- 20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship
Closely related versions have their own guide: BMW 220i B48 F22 / F23 2.0T, BMW 230i B48 G42 2.0L, BMW 330i B48 F30 2.0T, BMW 430i B48 F32 2.0T.
The turbocharged 4-cylinder: more character than you might think
The 4-cylinder turbo in your M135i F40 is a modern, solid engine, but BMW calibrated it for efficiency and silence, not for emotion. The result: an anonymous, flat factory sound. What few drivers know is that a turbocharged 4-cylinder responds very well to a well-engineered exhaust: by removing the unnecessary silencers and optimising the routing, you get a full, sporty and rewarding tone, with crisp crackles on the overrun.
The ROG exhaust delivers exactly that, and the controllable valves do the rest: character when you want it, total discretion when you need it.
How the exhaust on your BMW M135i B48 F40 is put together
Here is what the ROG exhaust replaces, and where the sound is shaped.
The cat-back is the complete exhaust system
It is everything you can see under your BMW M135i B48 F40, all the way to the tips: pipes, silencer, valves. This is the part where most of our research and development goes, the part that shapes the sound, and it fits without touching the engine or the ECU.
Your BMW M135i B48 F40 in figures
An exhaust system is judged first by ear and on the scales. The extra horsepower comes from an ECU remap.
Power
Torque
Published factory and Stage 2 figures.
The ROG exhaust works with or without an ECU remap. To get the full potential out of your BMW M135i B48 F40, we recommend taking it to an approved tuning centre afterwards.
To be completely transparent: on a turbocharged 4-cylinder, the exhaust alone mainly improves breathing and sound. The significant power gains come with Stage 2, the exhaust plus an ECU remap at an approved tuning centre, and the engine handles them with ease. It is the combination we recommend to anyone who also wants to transform performance.
Configuring your exhaust, step by step
3 choices, in the same order as the product page configurator.
-
Step 1 of 3: Material: stainless steel or titanium
For your BMW M135i B48 F40, the exhaust costs €2,490 in stainless steel and €2,990 in titanium.
304 stainless steel
€2,490
- Weight
- Baseline
- Sound
- Full and rounded
The safe bet: strong, corrosion-proof, with a full, rounded sound. The best value for money.
Titanium
€2,990
- Weight
- Around 40% lighter
- Sound
- Metallic, crystal-clear
It makes the exhaust around 40% lighter for the same design. Its note is more metallic and clearer higher up the rev range, and its finish ranges from brushed to blued.
No worries on durability: 304 stainless steel shrugs off winter road salt and titanium does not rust. Stainless steel or titanium: what really changes.
-
Step 2 of 3: Valves: ROG remote or factory control
Two ways to control the valves on your BMW M135i B48 F40.
ROG remote

A discreet control unit in the boot and a two-button remote: you open and close whenever you like, independently of the drive modes. For fitting, we support you by phone or by email.
Factory control
- Only for vehicles fitted with factory valves
- Controlled by the drive modes
For vehicles fitted with factory valves: the exhaust connects to their control and the drive modes stay in charge, with no extra control unit.
At 130 km/h, many sports exhausts drone. Here, with the valves closed, the exhaust flows through the silencer and stays composed when cruising; open, it makes itself heard when you choose. More about exhaust drone.
-
Step 3 of 3: Tips: the visual signature
Match the tips to the style of your BMW M135i B48 F40, understated or bold. A particular finish in mind? Send us a photo and we will look at it together.
- Stainless steel
- Black
- Carbon
- Blued titanium
- M Performance style carbon

The ROG sound signature on the 4-cylinder
Our optimised routing gives the 4-cylinder a full, sporty tone, far richer than the thin factory sound, with crisp crackles on the overrun with the valves open. The goal is not volume at any cost but a rewarding, controlled sound that becomes completely discreet again with the valves closed.

From order to fitting
-
Configuration
You configure the exhaust and enter the VIN from box E of your registration document or from the base of the windscreen.
-
Check
Your VIN is checked before any manufacturing begins.
-
Manufacturing
The exhaust is produced to order, for your vehicle.
-
Delivery
Free in Europe, insured parcel, tracking number from dispatch.
-
Fitting
Around two hours in the workshop, with no welding or cutting.
20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship, from the date of delivery
- Payment
- In instalments with Klarna
- Installation
- At the garage of your choice
Is your BMW M135i B48 F40 still under the manufacturer's warranty? In Europe, the manufacturer cannot refuse it simply because a part from another brand has been fitted: it is up to them to prove the fault comes from it. Our article on the manufacturer's warranty.
Our recommendations for your BMW M135i B48 F40
-
Daily driving
€2,490
- Stainless
- ROG remote
The best balance of price, sound and comfort.
View this configuration -
Enthusiast
€2,990
- Titanium
A lighter exhaust, with a more metallic note at high revs.
View this configuration -
Style
€2,990
- Titanium
- Blued titanium or black tips
An exhaust is seen as much as it is heard.
View this configuration
Every BMW M135i B48 F40 has its own history and use: if none of these profiles fits you, let's talk.
BMW M135i B48 F40: your questions
How much power does an exhaust add on the BMW M135i B48 F40?
As standard, the BMW M135i B48 F40 produces 306 hp and 450 Nm. The exhaust alone acts first on sound, breathing and weight; the extra horsepower comes from an ECU remap. With a Stage 2 build, the published figures reach 380 hp and 560 Nm.
Stainless steel or titanium: which material for the BMW M135i B48 F40?
For the BMW M135i B48 F40, the ROG exhaust costs €2,490 in stainless steel and €2,990 in titanium. Stainless steel is the safe bet, with a full sound; titanium makes the exhaust around 40% lighter and gives a more metallic note higher up the rev range.
Is the ROG exhaust loud all the time on the BMW M135i B48 F40?
No, that is the whole point of the valves. Closed, the BMW M135i B48 F40 stays comfortable; open, the engine breaks free. You choose at any moment.
Will a ROG exhaust pass vehicle inspection on the BMW M135i B48 F40?
The exhaust replaces the rear section of the exhaust system on the BMW M135i B48 F40, with no work on the engine or the ECU. Present the car with the valves closed.
How is the ROG exhaust fitted on the BMW M135i B48 F40?
With clamps and gaskets, no welding or cutting: around two hours in the workshop for a well-equipped mechanic. The exhaust is built to the VIN of your BMW M135i B48 F40.
What price and lead time for a ROG exhaust on the BMW M135i B48 F40?
From €2,490 to €2,990 depending on the configuration. Allow 20 working days from order confirmation to delivery. Delivery is free and the exhaust comes with a 3-year warranty.
Unsure about your configuration? Give us a call.
Stainless steel or titanium, ROG remote or factory control: the right choice depends on how you use your BMW M135i B48 F40. We take the time to talk it through before you order, with a reply within 24 hours. We are not here to sell to you over the phone: we help you choose, even if that means a cheaper option because it suits the way you drive.
ROG is a French brand, and the way we work comes down to one idea: an exhaust system should be sold with advice, not just a product page. More than 500 exhaust systems fitted and a rating of 4.9 out of 5.
Further reading
Read next
- Mercedes-AMG SLC43 R172 V6 biturbo: an open-air V6, the exhaust system guide The SLC43 is a compact roadster with a retractable hard top, which AMG equipped with a 3.0-litre twin-turbo...
- Mercedes-AMG E55 W211 V8 Kompressor: the wolf in a business suit, the exhaust guide With the E55 W211, AMG slipped a 476 hp, 700 Nm supercharged V8 into an E-Class that looks...
- Mercedes-AMG CLS53 C257: the return of the straight-six, the exhaust system guide A four-door coupé with flowing lines, the CLS53 C257 benefits from Mercedes' return to a layout the brand...