Mercedes CLA 45 AMG C117 / X117: unleashing the 2.0 AMG, the complete exhaust system guide

Your vehicle.

All our exhausts for this generation, version by version, are brought together on one page: Mercedes-AMG CLA45 C117 / X117 Valved Exhaust.

Unveiled at the New York Auto Show in March 2013 and open for orders the following summer, the CLA 45 AMG is the most radical version of the four-door coupé C117, a compact saloon with a sloping roofline built on the Class A W176 platform. It shares with the A45 and, a little later, the GLA 45 a landmark recipe: a 2.0-litre four-cylinder pushed to a power level previously reserved for six-cylinders, a dual-clutch gearbox and all-wheel drive. In 2015, Mercedes-AMG added the Shooting Brake X117 to the range, a coupé-estate with the same mechanical components. The next generation, the CLA 45 S C118 with the M139 engine, arrived in 2019. Between those two dates, the CLA 45 remains a very quick and very expressive car, but one whose voice is deliberately kept on a leash by its factory line.

Designation

Mercedes-AMG CLA 45 4MATIC

Body styles

Four-door coupé C117; Shooting Brake X117 since 2015

Launch

Orders from summer 2013; replaced in 2019 by the C118

Engine

M133: 2.0 litres, four-cylinder, twin-scroll turbo, direct injection

Power and torque

360 hp and 450 Nm, then 381 hp and 475 Nm (deliveries from September 2015)

Gearbox and drivetrain

Seven-speed AMG SPEEDSHIFT DCT, 4MATIC all-wheel drive

Factory valve

Yes: flap controlled according to load, revs and the chosen programme

Factory tips

Two twin outlets, one on each side

A compact saloon turned top-flight sports car

The standard CLA targets customers who want the look of a coupé in the format of a compact. The CLA 45 AMG keeps that silhouette but adds more open bumpers, a pronounced rear diffuser, larger brakes, a firmer chassis and an engine that puts the car on a level with far bigger saloons: 0 to 100 km/h falls under five seconds. It is this contrast between a reasonable size and the performance of a major sports car that made it a success.

The C117 coupé and the X117 Shooting Brake offer the same mechanics. The second, presented at the Geneva Motor Show in 2015, extends the roof to a tailgate and adds a real estate-car boot, without changing anything in the powertrain or the rear of the body under the floor. The Rog line is, moreover, identical for both body styles.

The M133, hand-built in Affalterbach

The M133 is a 1,991 cc four-cylinder that Mercedes-AMG builds according to its "one man, one engine" principle: each block is assembled by a single technician, who puts his signature on it. Aluminium block, direct injection, twin-scroll turbocharger blowing up to 1.8 bar: at its launch, it was the most powerful production four-cylinder in the world.

It has known two power levels. From 2013 to summer 2015, it is rated at 360 hp and 450 Nm. With orders opening in July 2015, and deliveries from September, it goes to 381 hp and 475 Nm, accompanied by a gearbox with shorter ratios. The Rog product page covers both versions and shows separate figures for each; your VIN tells us which one your car has.

Dual-clutch gearbox and 4MATIC transmission

The CLA 45 was only sold with the seven-speed AMG SPEEDSHIFT DCT, a dual-clutch gearbox that changes gear without interrupting traction. In sport mode, it holds gears longer and allows downshifts with an automatic throttle blip, which the Rog line makes clearly more audible.

The 4MATIC transmission sends most of the torque to the front wheels in relaxed driving and transfers a variable share to the rear when grip requires it. It has no influence on the exhaust line, which stays the same whatever the body style or the year.

The voice of the M133, held back by the standard line

A turbo four-cylinder of this power has a very particular sound character: a dull, gravelly idle, a quick, dry climb through the revs and a multitude of pops on lift-off. Mercedes-AMG was aware of this, since the CLA 45 already makes more noise than the other CLAs. But the factory silencers and the cabin insulation keep this voice within very well-behaved limits, particularly in Comfort programme, where you hardly hear more than a dull breath.

With the Rog cat-back, flaps open, the CLA 45 gains an immediate presence at start-up, a raspier grain under acceleration and much clearer crackles on deceleration. With the flaps closed, the gases pass through the silencers and the car returns to a sound level compatible with daily traffic or an early-morning departure.

Factory 360 hp version

Factory 381 hp version

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

The factory flap and the AMG programmes

According to Mercedes-AMG, the CLA 45 comes as standard with a large-diameter sports line fitted with an automatic exhaust flap, continuously controlled according to the driver's wishes, the load and the revs, the same solution as on the SLK 55 AMG of the time. An AMG Performance line with flaps, louder still, was offered as an option. The driving programme chosen on the selector also influences this control.

With the "Factory" option, the Rog line is delivered with the mountings provided for this system: your garage refits the car's control there, and the AMG programmes keep deciding when it opens. With the "Rog" option, the flaps are delivered fitted with a remote: you open or close them yourself, and they hold that position whatever programme is engaged.

Straight pipe or resonator on this four-cylinder

On a 2.0-litre engine, the choice of character matters more than on a V8, because the timbre of a four-cylinder can quickly become shrill. The straight pipe favours intensity: the M133's voice arrives as it is, with its high notes and its metallic side at high revs.

The resonator, at the same price, gives a rounder and slightly softer voice: the CLA 45 keeps its crackles and its presence, with fewer high notes on the motorway. It is often the right choice for a Shooting Brake that doubles as a family car.

Downpipe, materials and fitting

The part the product page calls "Manifold" is here the downpipe, the catalysed pipe attached to the turbo outlet. You can keep it and change only the cat-back. If you replace it, three versions exist: 200 cells, which keeps emissions control; 100 cells, accepted or not depending on your car and your country's rules; catalyst-free, which is intended for the track. The published Stage 2 figures assume this downpipe and a remap by a tuner; without the latter, the downpipe changes the sound, not the power.

304 stainless steel meets everyday use without constraint; titanium, about 40% lighter, comes brushed, gold or purple. The line is made in 20 working days to your VIN, delivered free of charge, with a 3-year warranty, and fitted by your garage with clamps and gaskets, with no welding or cutting.

Configure your exhaust.

How the exhaust is put together

On the CLA 45, coupé or Shooting Brake, the Rog line starts behind the downpipe and runs to the two twin outlets, silencers and flaps included. The catalysed downpipe that follows the M133's turbo is an option on the product page, under the name "Manifold".

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

Three recommended configurations.

• Everyday coupé

  • C117
  • Stainless steel
  • No manifold
  • Resonator
  • Factory valve

  For a CLA 45 that does the commute to the office every day: an M133 more present when you ask for it, a rounded voice at cruising speed and the original downpipe left in place.

  View this configuration

• Weekend Shooting Brake

  • X117
  • Brushed titanium
  • 200-cell sport manifold
  • Straight pipe
  • Rog remote

  For a 381 hp Shooting Brake that heads out on mountain roads: the raw grain of the four-cylinder, a turbo that breathes better and emissions control kept.

  View this configuration

• Tuned CLA 45

  • Purple titanium
  • 100-cell sport manifold
  • Straight pipe
  • Rog remote

  For a CLA 45 later entrusted to a tuner: the 100-cell downpipe, a lighter rear and tinted tips that stand out behind the diffuser.

  View this configuration

From order to fitting.

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

Questions.

Further reading.

• All our lines for the CLA 45 C117 and X117
• Mercedes-AMG A45 W176 guide, the same M133 in the hatchback
• Mercedes-AMG GLA45 X156 guide, the M133 in an SUV
• Mercedes-AMG CLA45 S C118 guide, the next generation