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Mercedes C 200 CDI
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Discussion Starter · #1 · (Edited)
Is durability affected by displacement? And if it isn't anymore until which year it was supposed to be? I guess durability of 2.2 liter engine from 2008. containing 200 hp is not affected by the size of displacement but what about the engines from the beginning of 2000's?

Some say that if there's 'a lot of HP on small displacement' the engine's more likely to weaken it's durability.
 

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2004 C230 Kompressor Sport Coupe
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Well, the 2.3l M111 has proven more durable than the 1.8l M271. They make about the same power. So that single data point says something.
 

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C230K Sport Sedan
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Engines are likely made to a durability spec, so if a manufacturer makes 4 different motors, the engineers that designed those engines were probably given a spec, make those engines last X number of miles. So they design the components and use materials as such to acheive their engineering goal. So one would think that say a V8 in the same car that can also have a I4 would last longer because it's not working as hard and many of us have seen cases where engines last an extrodinary amount of miles (had a buddy drove 95 miles each way to work in a 4 cylinder Pontiac Grand Am, laid it to rest with 300K miles). I know the M271 is a very poor design, probably designed in the middle of Oktoberfest by a team of drunk German's, but that has nothing to do with the intent of the question which I took it to mean, is a larger engine inherently more reliable than a smaller engine that's asked to do the same work and I think not.
 

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w204 (C350ELE)
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On the other side of the coin, I firmly believe that a larger power engine will last longer that one with less power. Why? Because it will be driven at a lower rpm, ergo less wear and tear. Nevertheless, road conditions, driving habits, maintenance, quality of supplies, engine design and materials, fuel admission, fuel burning efficiency... are all contributing factors. The bottom line: which engine (or vehicle) compared to which other? General statements are only misleading.

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Mercedes C 200 CDI
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Discussion Starter · #6 ·
OK, I see you want me to mention the engines. I got C 200 CDI from 2001. and I wanted you to compare it to C 220 CDI and C 270 CDI and also C 320 CDI from the same period, or W203 series because some of them may have not been produced at the same year.
 

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2017 GLC 300 4Matic fully loaded... but for the heated steering wheel. Stupid previous owner! 😠
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About vehicles with more power being pushed less than a car with less power, it is not true. There is absolutely no way that anyone here can honestly say that if they sold a car with 200 HP and bought one with 500 HP, that you never push that car at wide open throttle.
 

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2004 C230 Kompressor Sport Coupe
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About vehicles with more power being pushed less than a car with less power, it is not true. There is absolutely no way that anyone here can honestly say that if they sold a car with 200 HP and bought one with 500 HP, that you never push that car at wide open throttle.
Sure, but if it takes 80HP to get up to freeway speed in the time you regularly need, the 200HP car is working harder than the 500HP one, as a portion of total capability. A 100HP car can easily go speeds that are illegal in the entire country (think VW TDI).
 

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C230K Sport Sedan
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Still, the 200 HP motor is likely made knowing that it will be run harder than the 500 HP motor, so size is not a factor in how long a motor will last. The strains on the rest of the car would be greater with a 500 HP motor, given the same car. For example, I believe MB uses the same transmission in the C240 and C32 of the same year, so you have to figure that the stresses on the drivetrain with double the power would be greater with a C32 (assuming he bought a C32 because he wants to drive it harder). Also, to achieve double the HP using the same block must have it's challenges.
 

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Mercedes C 200 CDI
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Discussion Starter · #10 ·
If I've been misunderstood I want to empasize, I wanted to know if less PS/Litre meant durable engine.
 

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2004 C230 Kompressor Sport Coupe
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If I've been misunderstood I want to empasize, I wanted to know if less PS/Litre meant durable engine.
Basically what we are saying is: no, not as a general rule, only kind of as a guideline. Honda engines have high PS/Liter, but most are quite reliable. 1970s GM Diesels have very low PS/Liter, and are incredibly unreliable. 1990s Mercedes Diesels have relatively high PS/Liter and are quite reliable.
 

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It depends on a lot of things, but I think it's only meaningful if you're comparing similar engines.

I believe it's pretty well agreed that if you take two identical engines, and increase the displacement of one, the bigger displacement engine will make more power. So, if you want an engine with smaller displacement to make the same power, you have to resort to other methods, like raising the compression or forced induction, which put added stress on the engine. Think about it - the power of an engine comes from the force of the fuel exploding in the cylinders. The more powerful your explosions, the more powerful your engine, but more powerful explosions mean more stress on the components. The more power you want to get out of an engine, the more stress you put on it. Now, a good engineer will correctly measure the stresses on the engine parts and design them to endure, but engineers aren't perfect. The more power you squeeze out of an engine without increasing the displacement, the more stress it is under, and it becomes a question of how well it is designed. A manufacturer can probably safely take an engine (let's say a 4 cylinder) that was designed to make 180 hp, and bump it up to 205 or so without much re-engineering or problems. But if they try to get 350 out of that same engine without some re-design, they may start to impact reliability. That said, there are engines you can safely tune to that degree - it depends on the spec they were built to.

Now, the point. People want power, low vehicle prices, and fuel economy. So, car companies squeeze everything they can out of their small engines. Durability comes down to how well the engineers do their job, but a smaller engine making the same power as a bigger one will be under more stress - that's just physics. If I had a choice between a 6.0L V8 making 400hp and and 1.8L I4 making 400hp, I would expect the V8 to be more reliable. That doesn't mean it would always be true, though. The V8 could have been designed by idiots on a weekend and the I4 by geniuses over 20 years of racing experience.
 

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Mercedes C 200 CDI
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Discussion Starter · #13 ·
That was sort of answer I expected, DustInSunlight, considering what I was interested in. Excellent :goojob:

If you are into these engines, I would like to compare C 200 CDI and C 220 CDI from w203... redesigned they got about 20Nm and 6 PS more, it took place in 2004/05. I would like to know what are the good and bad sides of both, the way they were constructed, which engine was taken as ideal or standard when modelling these two which were mentioned.

And a glimpse at gasoline models which, you Americans, would be more competent to talk about than the diesels, what about the 1.8 petrol engine from the same car mentioned in the paragraph above with different kompressor powers. C 230K produces 190PS and there are also C 180K and C 200K with the same displacement but different PS.

If there's such specialist, please answer!

Thanks.
 

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2004 C230 Kompressor Sport Coupe
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We did not get the C180K or C200K in the USA, so specialists in that are unlikely to be here. With that said, the M271 was used in Formula 3, so it should be durable at much higher power levels and is likely unstressed even in C230K trim. Most of the problems in the USA are due to bad gas and low speeds, ie, head carboning.
 

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C230K Sport Sedan
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Still, you assume that two similar engines of different displacements but same HP are built the same and I doubt that. If you take a smaller engine and you yourself adds HP through aftermarket component, then yes, it will not last as long as the bigger engine because you didn't upgrade internal bits to make it last under the additional load.
 

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2002 C230 Sport Coup and 2006 ML350
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146K w/ ASP pulley and still running strong. Should I be worried?
 

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Surprisingly, a pulley kit won't shorten life that much because the car is rarely under any boost unless you floor it. I would bet that the amount of time your car is under boost in normal driving is less than 1%. Then you are only overdriving the s/c at near redline, probably not all that common in everyday driving.

146K w/ ASP pulley and still running strong. Should I be worried?
 
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