BMW 230i B48 G42: the small coupé that raises its voice, the exhaust system guide

Your vehicle.

All our exhausts for this generation, version by version, are brought together on one page: BMW 2 Series G42 Valved Exhaust.

The 2 Series Coupé G42 has stayed true to a recipe that has become rare: a compact coupé with a longitudinal engine and rear-wheel drive. The 230i is its most powerful four-cylinder version. Here is what you need to know about the car and its B48 before choosing a line.

Model

BMW 2 Series Coupé, type G42

Years

Presented in July 2021, on sale since 2022

Engine

B48: 2.0 litre inline four-cylinder, turbo

Factory output

245 hp and 400 Nm (230i); 184 hp and 300 Nm (220i)

Gearbox

Eight-speed Steptronic, Steptronic Sport optional

Drivetrain

Rear-wheel drive; xDrive offered in some markets

0 to 100 km/h

5.9 s (230i); 7.5 s (220i)

Range neighbour

M240i xDrive, 374 hp six-cylinder, with its own line

A rear-wheel-drive coupé, new generation

BMW presented the 2 Series Coupé G42 at the Goodwood Festival of Speed in July 2021, for a market launch in early 2022. It succeeds the F22 coupé and grows noticeably: 105 mm longer, 64 mm wider and 51 mm more wheelbase, with a height lowered by 28 mm.

The range opens with four-cylinders, petrol with the 220i, diesel with the 220d, and peaks with the six-cylinder M240i xDrive. The 230i slotted in between the 220i and the M240i in 2022. In Europe, the four-cylinder versions send their power to the rear wheels; in North America, the 230i also exists in xDrive.

220i or 230i: two tunes of the same B48

The 230i develops 245 hp (180 kW) and 400 Nm. It goes from 0 to 100 km/h in 5.9 seconds, with Launch Control standard on the automatic gearbox, and weighs about 150 kg less than the M240i xDrive, with a lighter front end.

The 220i makes do with 184 hp (135 kW) between 5,000 and 6,500 rpm, and 300 Nm between 1,350 and 4,000 rpm; it reaches 100 km/h in 7.5 seconds. Both share the B48, and the Rog product page assigns them the same line.

The bars below show, unchanged, the values of the product page for the 230i.

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

Between the 220d and the M240i xDrive

The 230i holds a place apart in the G42 range. Below it, the 220d pairs a twin-turbo diesel four-cylinder with 48-volt mild hybridisation, for 190 hp and 400 Nm, and 6.9 seconds from 0 to 100 km/h. Above it, the M240i xDrive moves up to the inline six: 374 hp, 500 Nm, all-wheel drive and 4.3 seconds to reach 100 km/h.

In between, the 230i keeps rear-wheel drive and a lighter engine over the front axle, for a quoted weight of around 1,600 kg. It is aimed at those who want a lively, balanced coupé rather than the brute force of the six-cylinder, and it is precisely on this kind of car that a more expressive line changes the feel at the wheel the most.

The B48, a four-cylinder from the BMW family

The B48 is a 2.0 litre inline four-cylinder with a turbo, which BMW also fits, among others, under the bonnet of the 330i F30 and 430i F32. On the G42, it gets an evolution whose exhaust manifold is integrated into the cylinder head, with revised forced induction and reduced emissions.

For the rear exhaust, this evolution does not change the logic: the Rog cat-back connects behind the downpipe, and your VIN confirms the exact version of your coupé.

Eight-speed Steptronic and rear-wheel drive

All 230i models use an eight-speed Steptronic gearbox; Steptronic Sport is among the options. An M Sport rear differential is also offered as an option.

The 230i is rear-wheel drive, which gives it a more playful behaviour than a front-wheel-drive car of the same power. This character deserves a more open voice than the one the standard line lets through, especially on a small road where the coupé is most at ease.

The voice of a turbo four-cylinder

A four-cylinder does not have the natural song of an inline six, and that is precisely why its exhaust matters so much. The B48 has more to say than you might think: a muted note at idle, a dry grain under acceleration and the breath of the turbo in the background.

On the standard 230i, the factory line smooths out almost all of this to keep the coupé discreet in town and on the motorway. With the flaps open, the Rog line gives the B48 a full sound that follows every rev climb; with the flaps closed, the 230i returns close to its original volume, for everyday journeys.

The result is felt mostly at mid-range, where the 230i spends most of its time: on a burst between two bends, the coupé gains a presence that accompanies the turbo's torque, then calms down as soon as the road straightens and you close the flaps.

Flaps controlled by remote

On this product page, the Rog line arrives with its flaps already fitted and a remote. Open, they stay open; closed, they stay closed, whatever driving mode is selected on the car. A small box fits in the boot, and two buttons are enough.

You therefore decide the volume independently of the coupé's behaviour: flaps closed to leave the garage early in the morning, open as soon as the road allows, without going through the vehicle's menus.

Rog tips or carbon tips with the M logo

The 230i G42 offers a wider choice of tips than most of our product pages. On one side, Rog tips in chrome, gloss black or blued titanium; on the other, carbon tips with the M logo, in forged carbon, black carbon or carbon and titanium. You can also order the line without a fitted tip.

The carbon tips go well with coupés fitted in M Sport trim; blued titanium or gloss black suit a more discreet 230i that does not seek to show off its upgrade.

Stainless steel, titanium and sound character

As for material, 304 stainless steel withstands winter salt and damp without faltering, with a full sound. Titanium, about 40% lighter for the same design, makes the B48's note clearer and more metallic in the revs; it comes in brushed, gold or purple.

For character, two options at the same price. The straight pipe keeps the dry grain of the four-cylinder and its pops when you lift off; the resonator gives it a rounder and slightly softer voice, which suits a 230i driven every day.

The optional downpipe, and what the line does on its own

The product page also offers the front section, under the name "Manifold": on this turbo engine, it is the downpipe that leaves the turbo and carries the catalytic converter. In 200 cells, the B48's emissions control is maintained; the 100-cell version depends on the car and the country; the catalyst-free version is intended for the track.

With BMW's map, the downpipe adds volume and saves a little weight, but not a single horsepower. The power figures published on the product page assume this front section and a remap carried out by a tuner. Rog makes your line to your VIN; your garage fits it without welding or cutting.

Configure your exhaust.

How the exhaust is put together

On the 230i and 220i G42, the Rog line starts at the downpipe connection and reaches the outlets: pipes, silencers and flaps. The downpipe, which follows the B48's turbo and contains the catalytic converter, forms the front section; 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.

• The everyday coupé

  • Stainless steel
  • No manifold
  • Resonator
  • Rog remote

  For a 230i that serves at the office as at the weekend: the B48 gains substance, the factory front section stays in place, the resonator rounds off the tone and the remote sets the volume.

  View this configuration

• Small roads

  • Titanium
  • 200-cell sports catalytic converter
  • Straight pipe
  • Carbon tips with the M logo

  For a 230i taken out on winding roads: 200-cell downpipe that keeps the emissions control and gives the four-cylinder more relief, lighter titanium, and carbon tips for the look.

  View this configuration

• Trackday

  • Titanium
  • Decat
  • Straight pipe
  • Rog remote

  For a 230i prepared for the track: catalyst-free downpipe reserved for circuit use, straight pipe for the B48's raw grain, and flaps open from the first lap to the last.

  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 2 Series Coupé G42
• BMW M240i G42 guide, the six-cylinder version
• BMW 220i F22 / F23 with B48 engine guide