Mercedes M271 Tuning

"All you need to know about tuning and performance parts on the Mercedes M271 engine!"

Let us examine the options for your M271 tuning and provide tips on the ultimate upgrades. Mercedes M271 have loads of potential and with carefully chosen uprated parts like a remap, turbo upgrades and camshafts you will substantially improve your driving enjoyment.

History, Power & Specs of the Engine

Power output ranged from 122–204 PS (90–150 kW; 120–201 hp)

This solid engine was chosen for formula 3 racing and makes a great basis for your tuning project.

KE18ML (271.95X) 1.8 L 

  • 2002 Mercedes-Benz CLK-Class (W209) CLK 200 KOMPRESSOR
  • 2002 Mercedes-Benz C-Class (W203) C 180 KOMPRESSOR, C 200 KOMPRESSOR
  • 2002 Mercedes-Benz C-Class Sportcoupé CLC 180 KOMPRESSOR, CLC 200 KOMPRESSOR,
  • 2002 Mercedes-Benz E-Class (W211) E 200 KOMPRESSOR
  • 2004 Mercedes-Benz E-Class (W211) E 200 NGT (bi-fuel - gasoline + natural gas)
  • 2004 Mercedes-Benz SLK-Class (R171) SLK 200 KOMPRESSOR
  • 2007 Mercedes-Benz C-Class (W204) C 180 KOMPRESSOR, C 200 KOMPRESSOR
  • 2008 Mercedes-Benz CLC-Class CLC 180 KOMPRESSOR, CLC 200 KOMPRESSOR

DE18ML (271.9XX) 1.8 L 

  • 2003 Mercedes-Benz C-Class Sportcoupé C 200 CGI
  • 2003 Mercedes-Benz C-Class (W203) C 200 CGI
  • 2003 Mercedes-Benz CLK-Class (W209) CLK 200 CGI

KE16ML (271.910) 1.6 L

  • 2008 Mercedes-Benz CLC-Class CLC 160
  • 2008 Mercedes-Benz C-Class (W204) C 180 KOMPRESSOR

DE18LA (M271Evo, 271.8XX) 1.8 L Turbocharged

  • 2009 Mercedes-Benz C-Class (W204) C 180 CGI, C 200 CGI, C 250 CGI
  • 2009 Mercedes-Benz E-Class (W212) E 200 CGI, E 250 CGI
  • 2010-2013 Mercedes-Benz E-Class (C207) E200 BlueEfficiency
  • 2009-2011 Mercedes-Benz E-Class (C207) E250 CGI
  • 2011-2015 Mercedes-Benz SLK-Class (R172) SLK 200, SLK 250

Tuning the Mercedes M271 and best M271 performance parts.

Best M271 parts

Just because particular upgrades are are common on M271 it doesn't mean it is good, instead we'll optimum upgrades that will give your M271 the best value for money to power increase.


Altering your M271 camshaft will make a dramatic difference to the engine engines power. Choosing a higher performance camshaft profile raises the engines power accordingly.

Fast road camshafts tend to increase the performance throughout the rev band, you may lose a little low end torque but your top end will improve.

Motorsport and race camshafts, increase the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport camshaft makes it harder when on the daily commute, because the lumpy idle will make the car prone to stall and smooth driving at low rpm becomes impossible. If you are developing a track car this doesn't matter as you are in the high end of your RPM range anyway and that is where you want the power to be.

You should ideally match your engines power to your cars usage so for a daily driver stick with a fast road M271 camshaft

Each engine responds better to mild camshaft durations so set your engine up on a rolling road.

The ecu map and injectors and fuel pump also have an effect on the bhp gains you'll hit.

Longer valve durations can alter the bhp band and on most engines the exhaust and intake durations do not need to match, although most cams and tuners use matched pairs there are some advantages to extending the intake or exhaust durations.

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Best Engine Mods for your car

  1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
  2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
  3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
  4. Upgrades to turbochargers and superchargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
  5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.

Typical stage 1 mods often include: Remaps/piggy back ECU, Sports exhaust header/manifold, Panel air filters, Intake manifolds, drilled & smoothed airbox, Fast road camshaft.

Typical stage 2 mods often include: Ported and polished head, Sports catalyst & performance exhaust, fuel pump upgrades, high flow fuel injectors, induction kit, Fast road cam.

Typical stage 3 mods often include: Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Twin charging conversions, Internal engine upgrades (head flowing porting/bigger valves), Competition cam.


Carefully think through your options and then source your parts and set yourself a power target to avoid wasting your time and money.


remap should help to release the full potential of all the mods you've done to your M271.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

It will usually give you around 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but power output may vary depending on the mods you've applied and the condition of your engine.

Pushing air into your M271 is vital to any performance tuning job.

Intake flow the air during the suck phase from the intake filter and allow it to be pulled into the engine cylinders.

The size of bore and shape and flow rate of the Intake can make a large effect on to fuel delivery on the M271.

We often see intake manifold are ripe for a performance upgrade, although a few manufacturers provide fairly well optimized intake manifold.

Increasing the M271 valve size, doing a bit of port matching and head flowing will also increase power, and as an added benefit will permit an improved power increase on other tuning mods.

Turbo upgrades

NA (naturally aspirated) engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your M271

The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes significant power gains.

When the engine has a turbo already fitted upgrades are more reliable and we find turbo charged engines already contain strengthened components.

However engines have weakspots

We recommend you find these limits and install higher quality components to handle the power.

We've seen car owners spending a lots of money on turbo charger upgrades on the M271 only to watch the motor throw a rod soon after it's first rolling road session.

Larger upgraded turbo chargers commonly experience a bottom end lag, and smaller turbo chargers spool up quickly but do not have the peak end torque gains.

We are pleased that the range of turbo units is always evolving and we commonly find variable vane turbo units, allowing the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbo units divert the exhaust gases into two channels and flow these at differently profiled vanes in the turbo. They also help the scavenging effect of the engine.

It is not unusual that there's a restriction in the air flow sensor (AFM/MAF/MAP) on the M271 when a lot more air is being fed into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited bhp and torque at a much lower level.

Adding a supercharger or additional turbo will make large bhp gains, although harder to setup. We have this article covering twinchargers if you want to read more.


You will need to ensure that the engine is not starved of fuel so must increase the fuelling when you start extending past 20% of a power increase.It is important to over specify your injector capacity.


As a rule of thumb add 20% capacity when buying an injector, this allows for injector deterioration and provides a bit of spare capacity should the engine require more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

All the following flywheel power targets will assume an injector duty cycle of 80% and a base of 58psi of fuel pressure at idle.

4 Cylinder turbocharged engines

  • 58 PSI 340cc/min 200hp
  • 58 PSI 511cc/min 300hp
  • 58 PSI 682cc/min 400hp
  • 58 PSI 1022cc/min 600hp

5 Cylinder turbocharged engines

  • 58 PSI 273cc/min 200hp
  • 58 PSI 409cc/min 300hp
  • 58 PSI 545cc/min 400hp
  • 58 PSI 818cc/min 600hp

4 Cylinder NA (naturally aspirated) engines

  • 58 PSI 285cc/min 200hp
  • 58 PSI 426cc/min 300hp
  • 58 PSI 568cc/min 400hp
  • 58 PSI 853cc/min 600hp

4 Cylinder supercharged engines

  • 58 PSI 312cc/min 200hp
  • 58 PSI 468cc/min 300hp
  • 58 PSI 625cc/min 400hp
  • 58 PSI 937cc/min 600hp


You only need to uprate your exhaust if the current exhaust is creating a restriction in flow.

On most factory exhausts you'll find your flow rate is still fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Do not go with the largest exhaust you can buy you'll reduce the exhaust flow rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Typically exhaust restrictions are in the catalyst installed, so adding a higher flowing performance catalyst removes the restriction. We note that performance cats perform similarly to decats and have the added benefit of keeping your car street legal, as decats or catalyst removal is illegal in most territories for road going cars.

Weak spots, Issues & problem areas on the M271

The M271 engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the M271, especially when tuned and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice on Tuning your M271 engine please join us in our friendly forum where you can discuss tuning options in more detail with our M271 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We love hearing about our website visitors projects, especially the mods done and which work best for you on your car. Which helps us keep our guides and tips up to date helping others with their modified car projects. Your feedback and comments are used to keep this page up to date, and help improve the accuracy of these M271 tuning guides which get regular updates and revisions.


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