Mercedes A45 AMG W176: giving the M133 its voice back, the complete exhaust system guide
RogMotorsport expert guide
When the A45 AMG arrived, no production 2-litre in the world did better: 360 hp from 1,991 cc, an engine hand-built in Affalterbach. Ten years on, the W176 remains a benchmark, but its factory exhaust has never told the story of what lies under the bonnet. This guide explains everything you need to know before choosing your configuration: cat-back only or sport catalytic converter, emissions control, engine warning light, stainless steel or titanium, and the valve system.
The M133: the four-cylinder that set a record
The 2.0 turbo in your A45 AMG W176 is called the M133, and it is the first turbocharged four-cylinder developed entirely by AMG. When it was launched, it held the world record for specific output from a production engine: 360 hp at 6,000 rpm and 450 Nm available from 2,250 to 5,000 rpm, around 181 hp per litre. No other production 2-litre engine could do that. To get there, AMG reworked the engine in depth: a sand-cast aluminium crankcase, forged steel crankshaft, forged pistons, NANOSLIDE-coated cylinder liners (the process used on the SLS's M159 V8) and a twin-scroll turbocharger. All of it hand-assembled according to the "One Man, One Engine" principle, with the engine builder's signed plate.
This engine was paired with the 7G-DCT dual-clutch gearbox and 4MATIC all-wheel drive. Technically, everything is there. What is missing is the soundtrack: the factory silencers are oversized and almost completely erase the engine's character. The ROG exhaust fixes that without touching the factory electronics. A point of reference before reading the table: the figures below are based on the 360 hp version, the one produced before the facelift.
The figures: what the exhaust system really delivers
At ROG, we always look for the best. That is why we always recommend an ECU remap at an approved tuning centre after installation. Our systems fit perfectly with or without, but it is with a full remap that your engine will express all of its potential.
| Factory | ROG system alone | Stage 2 + Remap | |
|---|---|---|---|
| Power | 360 hp | 369 hp (+9 hp) | 460 hp (+100 hp) |
| Torque | 450 Nm | 462 Nm (+12 Nm) | 570 Nm (+120 Nm) |
| System weight | ~18 kg | ~12 kg stainless steel ~9 kg titanium |
— |
Gains from the ROG system alone without a remap. Stage 2 with a full remap.
Let's be frank: the exhaust alone brings a modest gain, purely through reduced back pressure. The M133's true potential is unlocked at Stage 2: exhaust plus an ECU remap at an approved tuning centre. It is one of the most responsive four-cylinders on the market, and the figures above stay well within its working range.
A word about the bottom row of the table, the one people look at least and which matters a great deal: weight. The factory exhaust system on your A45 AMG W176 weighs around 18 kg. In stainless steel, the ROG exhaust comes down to around 12 kg; in titanium, to around 9 kg. That is weight taken off the rear and the underside of the car, exactly where it hurts most.
Cat-back only or sport catalytic converter: building your configuration
Let us start with a point many websites keep quiet about: you do not have to touch the catalytic converter. Our full post-cat exhaust system, the cat-back, is already a major transformation. It houses the entire valve system and removes a large part of the factory silencers. In sound, character and breathing, the gain is immediate, with the best results for the money. It is the ideal starting point and, for many of our customers, it is more than enough.
Changing the catalytic converter is then for those who want to go further: even more flow, even more sound. Here is exactly what each option means for your A45 AMG W176.
200-cell sport catalytic converter
Emissions control remains complete. The 200-cell converter keeps full catalytic treatment: the monolith is simply less dense than the factory one, which lets noticeably more flow through with reduced back pressure. It is the configuration that departs least from factory operation, and the one we recommend for a car used every day.
100-cell sport catalytic converter
Half as many cells. Flow comes close to that of a straight pipe and the sound gains real aggression, especially at high revs. Emissions control is still there, but clearly reduced compared with the 200-cell converter. It is a choice geared towards performance and sound, to be made with full knowledge of the facts depending on your use.
Decat
The decat pipe removes all emissions control: maximum flow, raw sound and the sharpest revving. It is the most extreme configuration we offer, and the only one that removes exhaust gas treatment completely. The choice is yours, made with full knowledge of your situation and how you use the car. If in doubt, call us and we will talk it through.
Sound level, on a scale of 0 to 10
To give you a concrete idea, here is how the configurations rank on your A45 AMG W176, with the valves open:
And remember: with the valves closed, every one of these configurations becomes discreet again. That is the whole point of the ROG valve system.
What about the engine warning light?
A question we always get, answered with figures. With a sport catalytic converter (100 or 200 cells), an engine warning light appears in around 15% of cases. A warning light is therefore very rare, but the risk is not zero. With a decat, the warning light is more common, as the ECU detects the missing emissions control. Either way, the fix is simple: a diagnostic tool session or an ECU remap will clear it. And if it happens to you, get in touch and we will help you through it.
Stainless steel or titanium: what difference does it make for you?
Stainless steel (304 grade): the benchmark for high-end exhausts. Tough, durable and corrosion-proof, with a full, rounded sound. It offers the best value for money and is the choice of most of our customers.
Titanium: around 40% lighter than stainless steel, with a more metallic sound signature that turns crystalline at high revs. It is also an aesthetic choice: titanium comes in several shades, from natural titanium to heat-blued burnt finishes. It is the material of supercars and motorsport. On an A45 AMG W176, it brings an exclusive character that stainless steel simply cannot offer.
The ROG sound signature on the AMG 2.0
The M133 has the voice of a racing engine that the factory exhaust almost completely smothers. Our exhaust gives it back: a fierce, full tone, an aggressive climb through the revs and rich crackles on the overrun with the valves open. Valves closed, the W176 goes back to being the discreet hatchback it has always known how to be. Two cars, one exhaust.
The valve system: how it works, and why it changes everything
The principle is simple and mechanical. With the valves open, the exhaust gases run straight through: a direct path, no restriction, maximum sound and flow. With the valves closed, the gases are forced through the rear silencer: the volume drops immediately, the car becomes discreet again and the noise level stays within regulatory limits. Two personalities in one exhaust system, and you are the one who decides.
You have two ways to control these valves, whichever you prefer.
OEM valves: the exhaust is supplied with mounting points to refit your factory actuators. Your A45 AMG W176 keeps all of its factory management: drive modes and automatic opening according to the manufacturer's mapping. Zero added electronics, completely seamless integration.
ROG remote-controlled valve system: new motorised valves, independent of the factory engine management. A small control unit fits in the boot (very simple installation, full guide shipped with the exhaust), and a remote gives you two buttons: open and closed. You decide, at any moment, whatever the drive mode. Discreet in your street at 7h00 in the morning, spectacular on a mountain road at the weekend.
The tips: the visual signature
Final step of the configuration: the exhaust tips. Shapes, diameters and finishes of your choice, to match the exhaust outlets to the style of your A45 AMG W176, whether understated or bold. Something specific in mind, a particular finish? Email us a photo or a description and we will work out together what can be done.
ROG semi-bespoke: why we ask for your VIN
Every exhaust system is assembled for your exact specification. That is why, before ordering, you enter your vehicle's exact details (year, model, engine, chassis) along with your 17-character VIN, shown in box E of your vehicle registration certificate. This is not a formality: it is what allows us to guarantee a perfect fit, with no nasty surprises during installation. Installation is plug and play, with no modification to the vehicle.
On lead times, we are transparent: allow around three weeks between your order and dispatch, one week of design and two weeks of manufacturing. This is not something picked off a shelf, it is an exhaust system we build for your A45 AMG W176.
A French brand, close to its customers
RogMotorsport is a French brand, and we built it around one conviction: with a product like an exhaust system, the support matters as much as the product itself. In practice, this means you can reach us by phone on 07 56 95 95 39 or by email at contact@rogmotorsport.com, before, during and after your order.
Before ordering: torn between stainless steel and titanium, between a 200-cell converter and a cat-back only, or want to know what suits your use best? Call us, we will take the time. Do you have a specific request, particular tips, a special finish, or a question about your exact configuration? Write to us and we will give you a straight answer. After your order: tracking, fitting advice and support if needed. It is that closeness that makes the difference.
Configure my exhaust for the A45 AMG W176 (from €2,405)
In summary: our recommendations for the A45 AMG W176
Daily driving, open road: cat-back exhaust or 200-cell catalytic converter, ROG remote-controlled valves. A character transformed every day, with the volume under your control from the first mile to the last.
Enthusiast use: titanium, 100-cell catalytic converter and a Stage 2 ECU remap to unlock the full potential.
Ultimate configuration: decat, full Stage 2. The absolute maximum in flow and sound.
And if you are still unsure, that is perfectly normal: it is exactly why we answer the phone.
Frequently asked questions
MERCEDES A45 AMG W176 (2013-2018): your questions
What power gain does the ROG exhaust give on a MERCEDES A45 AMG W176 (2013-2018)?
The MERCEDES A45 AMG W176 produces 360 hp as standard. With the ROG exhaust alone, without an ECU remap, it rises to 369 hp, a gain of +9 hp, and torque goes from 450 Nm to 462 Nm (+12 Nm). With a full Stage 2 ECU remap, the package reaches 460 hp (+100 hp) and 570 Nm (+120 Nm).
How much weight do you save on a MERCEDES A45 AMG W176 (2013-2018)?
The factory exhaust on the MERCEDES A45 AMG W176 weighs around 18 kg. The ROG stainless steel exhaust weighs around 12 kg, which is 6 kg less. In titanium, it drops to around 9 kg, which is 9 kg less than the factory system.
Do I need an ECU remap after fitting?
It is not compulsory: the ROG exhaust system works with or without an ECU remap. ROG does, however, recommend one at an approved tuning centre, because it is with a full ECU remap that the engine shows its full potential: the difference is 369 hp without, against 460 hp with.
How do the valves work, and is it loud all the time?
No. The valve system controls how the exhaust opens: with the valves closed, the gases flow through the silenced path and the noise level stays within regulatory limits; with the valves open, they take the straight-through path and the exhaust sound comes through in full. You choose at any moment, which means you can use the MERCEDES A45 AMG W176 every day without putting up with the volume all the time.
Which configurations are available, and which one should you choose?
The ROG exhaust system is semi-bespoke: you choose the material (stainless steel or titanium), the manifold (no manifold, 200 or 100-cell sport catalytic converter, or decat), valve control (factory actuators or ROG remote-controlled valves) and the tip finish. Every combination changes the sound and the character of the car. The guide above details what each element changes on the MERCEDES A45 AMG W176.
How much does a ROG exhaust cost for a MERCEDES A45 AMG W176 (2013-2018), and how long does it take?
For the MERCEDES A45 AMG W176, prices range from €2,405 to €3,760 depending on the chosen configuration (material, manifold, valves, tips). As every exhaust system is built for your vehicle, allow around three weeks between order and dispatch: one week of design, two weeks of manufacturing.
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