BMW 340i F30 / F31: unleashing the B58, the complete exhaust system guide

Your vehicle.

All our exhausts for this generation, version by version, are brought together on one page: BMW 3 Series F30 / F31 Valved Exhaust.

The 340i holds a place of its own in the long history of the F30-type 3 Series: it is the first to carry the B58, the engine that took over from the N55 and that BMW then rolled out across its range. It arrives with the 2015 facelift, replaces the 335i at the top of the standard range and remains, for many enthusiasts, the best-balanced sports sedan of its generation. Here is what you need to know about it before choosing an exhaust.

Model

BMW 340i, at the top of the standard F30 3 Series range

Body styles

F30 sedan and F31 Touring, on the same Rog product page

Model years

On sale from 2015; our product page covers 2016 to 2018

Engine

B58, single-turbo inline six-cylinder, 2,998 cc

Power and torque

326 hp and 450 Nm, this torque available from about 1,380 rpm

Drivetrain

Rear-wheel drive, or xDrive all-wheel drive depending on the order

Transmissions

Eight-speed automatic, or six-speed manual depending on the version

Predecessor

335i F30, N55 engine, which has its own guide

What the 2015 facelift changed

With the facelift presented in 2015, the 3 Series receives new LED headlights, reworked bumpers and above all a new generation of engines. Under the name 340i, the B58 takes the place of the 335i's N55; alongside it, the 330i adopts a 2.0-liter four-cylinder. The hierarchy of the range remains clear: the top of the pyramid is still a six-cylinder, and that is the one we are looking at here.

The 3 Series of this period comes as a sedan, code F30, and as the Touring wagon, code F31. Other body styles share the platform, such as the Gran Turismo, but our product page is for the sedan and the Touring. The VIN, supplied with the order, confirms that it is indeed one of these two body styles before any production work.

The B58, a six-cylinder from another generation

The B58 is a 2,998 cc inline six-cylinder, boosted by a single twin-scroll turbo. Its block is closed-deck and particularly rigid, and BMW designed it as a modular base that is then found in many models, up to the Toyota GR Supra. In the 340i, it develops 326 hp and 450 Nm, with a torque plateau that runs from about 1,380 to 5,000 rpm.

In practice, the car pulls smoothly as soon as you touch the throttle and does not tire before the upper part of the rev counter. The B58 is also seen as a robust engine, one that handles increases in load well: the Rog product page publishes its factory values and those of a strong tune, without the cat-back needing a remap.

The product page's performance table sits just below; it is a reminder that the extra horsepower comes from the ECU, not from the exhaust alone.

Stage 2: published figures with the front section and an ECU remap carried out by a tuner.

F30 sedan or F31 Touring

The two body styles look alike beneath the floor: same wheelbase, same muffler positions, same mechanicals. The Rog system is therefore the same for the sedan and the wagon, which explains a single product page. The Touring offers a larger trunk, which families appreciate.

On the Touring, the large volume at the rear slightly changes how the sound is perceived on board. A wagon lets low frequencies resonate more easily, and that is one more argument for considering the resonator version if you often drive with the family.

Rear-wheel drive or xDrive

The 340i is sold in rear-wheel drive and in xDrive, the brand's all-wheel drive. The choice affects behavior in the wet and the weight of the car, but not the routing of the exhaust that concerns us: the cat-back is made to the VIN, so your car's configuration is taken into account when you order.

Drivers who cover a lot of miles in winter or in the mountains have one more reason to prefer 304 stainless steel, a material very tolerant of road salt.

The B58's voice as BMW delivers it

A turbocharged inline six-cylinder has a naturally continuous, slightly metallic timbre, which people readily associate with sporty 3 Series. On the standard 340i, this character is rarely perceptible: the large-volume muffler, designed to respect noise limits, smothers the engine's voice and reduces it to a distant breath, even at a brisk pace.

You hear more of the transmission, the road noise and the wind turbulence than the engine itself. This observation is the first reason why the car is among those our customers ask us to set free.

What the Rog exhaust changes

With the valves open, the B58 regains a round bass on start-up, an even climb through the revs and, on lift-off, clear crackles. The voice remains that of an inline six-cylinder: smooth, without the flash of a V8, but with a more assertive grain than the original.

With the valves closed, the sedan or the Touring becomes an everyday car again, reserved in town and on the main roads alike. One and the same vehicle thus plays two roles, depending on the position of the valves, with no compromise on daily comfort.

On our scale of 0 to 10, the factory exhaust sits at around 3; the Rog cat-back alone reaches 7, valves open.

The valves: fitted by Rog and operated remotely

The valves are fitted to the exhaust and operated by a two-button remote, linked to a small control unit placed in the trunk. Open, they stay open, whatever drive mode is selected; closed, they stay closed. You therefore decide on the volume at every moment.

Rog makes the exhaust to the VIN, and your garage fits it without welding or cutting, with clamps and gaskets.

Stainless steel or titanium

304 stainless steel offers a full, round sound. It ages well, copes with winters and remains the choice of peace of mind for a car used all year round. Titanium lightens the exhaust by about 40% for the same design and gives a brighter, more metallic note in the revs.

Titanium is ordered in three shades: brushed, gold or purple. Brushed suits a restrained 340i, gold makes the tips stand out on a dark body, and purple asserts a more marked personality.

Straight pipe or resonator

The sound character is set at the same price. The straight pipe keeps all the B58's grain, unfiltered, with sharp attacks; it appeals to those who want to hear the engine up close. The resonator gives a rounder and slightly softer voice, which Touring owners and those who cover long distances readily choose.

Whichever character is chosen, the stance remains frankly sporty: only the roundness of the note varies, not its assurance.

The downpipe, as an option

Under the name "Manifold", the product page offers the B58's downpipe, the pipe that extends the turbo and contains the catalytic converter. The 200-cell version keeps the emissions control; the 100-cell version depends on the vehicle and the rules of the country; the catalyst-free version is intended for the track.

Fitted alone, without a map, this part changes only the sound and the weight of the whole. With a map made by a tuner, it makes it possible to exploit the engine's potential. The "No manifold" position keeps the factory front section.

The tips

Four Rog finishes are offered: chrome, gloss black, blued titanium or no tips. The carbon tips with the M logo come in black, titanium or forged. This choice changes the 340i's rear look, not its sound.

A carbon finish suits a 340i with the sport pack well, while chrome goes with a more classic version.

The model years covered

Our product page lists the 2016 to 2018 model years. Yet the 340i was built from 2015, and the F30 3 Series ended in 2019. If your car falls outside this range, please send us the VIN before ordering: we check compatibility and confirm whether we can build it, with no commitment.

Configure your exhaust.

How the exhaust is put together

On the 340i, the Rog exhaust starts at the downpipe connection, under the floor, then follows the tunnel to the mufflers, the valves and the two rear tips. The B58's downpipe, right after the turbo, forms the front section with its catalytic converter; the product page offers it as an option, under the name "Manifold".

Each choice explained in detail, from sound to material: How to configure your exhaust.

Three recommended configurations.

• Everyday 340i

  • Stainless steel
  • No manifold
  • Resonator
  • Rog remote

  For a 340i used every morning: factory front section, the B58's note rounded by the resonator and valves that you close in traffic.

  View this configuration

• Touring for the road

  • Brushed titanium
  • 200-cell sport manifold
  • Resonator
  • Rog remote

  For an F31 Touring heading off for the weekend: lighter titanium, 200-cell downpipe that keeps the emissions control, and a resonator against the bass of the big trunk.

  View this configuration

• Sedan for the track

  • Gold titanium
  • Catalyst-free manifold
  • Straight pipe
  • Rog remote

  For a sedan taken out on track: straight pipe, catalyst-free downpipe reserved for the circuit and gold tips that stand out in the paddock.

  View this configuration

From order to fitting.

VIN, manufacture, delivery, fitting and warranty, step by step

Questions.

Further reading.

• All our lines for the BMW 3 Series F30 / F31
• All our B58-engined exhausts
• BMW 335i F30 guide, the N55 that preceded the B58
• BMW 330i B48 F30 guide, the four-cylinder 3 Series
• BMW M340i G20 guide, the next generation's B58