I have asked this question on the benz forum but seems the thread has shifted base to WhatsApp.

I never knew there's a diesel engine for Mercedes car c-class until I saw a 2003 c220 cdi. I was curious and wondered what they're aiming to achieve with that in the small car. Compare to Gas engine, how efficient, any advantage or minus, what is the maintenance compare to petrol engine, any known specific problems for the engine, and does it requires special technical know how or anyone with mercedes experience can handle Please share your experience and let's learn.

Cc: Siena, thefakestan, amzee, ikenna351 etc.

Siena:
Mercedes-Benz have always had diesel engine options across the range. The VE (volumetric efficiency) of a diesel engine is superior to that of the equivalent gasoline engine. The diesel engine has advanced more in the last 30 years than the gasoline versions have in the last 80. Performance is pretty much the same these days, and the traditional diesel clatter has reduced, to the point it's barely audible.

Diesel engines have a longer service life compared to the equivalent gasoline version, as there is less heat involved. The actual diesel block is also much more rigid than a gasoline equivalent. There are no spark plugs to replace when it comes to servicing, and the service intervals are generally longer. But...

Diesel engine require more expertise. They require good quality oil, and the injectors are a lot more expensive than gasoline ones when they go wrong. Unlike gasoline injectors, they are calibrated cylinder-specific. Mix them up, and you'll have to set the injection volume. This requires dedicated OBD software.

Leaking diesel injectors will dilute the engine oil, if the oil level rises too high, it will get sucked up into the intake. This will cause the engine to rev unchecked, past the speed governor in the diesel injection pump. You won't be able to stop it, not even if you switch off the ignition. If you have the presence of mind to shove the gearshift into 5th, and dump the clutch, you can stall the engine. Otherwise, the engine will simply rev itself to destruction.

Later diesel engines from approx. 2007 have a DPF (Diesel Particulate Filter) as part of the exhaust system. They need to be really hot to be efficient. If you only cover short trips, forget about buying a modern diesel-engined Mercedes-Benz. The DPF will seldom reach optimum operating temperature, and will eventually become clogged with soot, engine performance will drop off, and fuel consumption will increase. If you're lucky, a 30 mile drive at 4000 rpm in 3rd gear may clear the soot blockage. If you're unlucky, it won't, and a replacement DPF will be your only option.

If you mostly do highway speeds on a regular basis, and cover over 10,000 miles per annum, the diesel-engined Mercedes-Benz is ideal - it'll eat up the miles effortlessly, it will return up to 58 mpg in the C-Class, it has immense pulling power, making its maximum torque from as low as 2000 rpm. The extra weight of the diesel engine up front will be evident, though with RWD it shouldn't be an issue. The 2.0 common-rail turbo diesel is best matched with automatic transmission, for smooth, and seamless performance.

If you do lots of city driving, and cover less than 10,000 miles per annum, you're best off with a gasoline-engined Mercedes-Benz. Or at least a pre-DPF diesel, meaning no newer than 2006.

Good luck!

Beautiful piece, thanks a lot. The bolded got me cringing though. How do you prevent this?

And Siena just gave us a lesson. Now, others won't comment because he has said it all. No wonder topics in Car talk section rarely make front page.

Sir,
I use C180 (W202). 1999 model
What causes cranking during motion?
I am not sure if it's cranking / racking or sort off. But it does happen some times when gear automatically want to switch itself from lower gear to high gear,at that point I use to take my feet off the gas pedal and press gently so as to minimize the racking sound. Thanks

Siena:
Mercedes-Benz have always had diesel engine options across the range. The VE (volumetric efficiency) of a diesel engine is superior to that of the equivalent gasoline engine. The diesel engine has advanced more in the last 30 years than the gasoline versions have in the last 80. Performance is pretty much the same these days, and the traditional diesel clatter has reduced, to the point it's barely audible.

Diesel engines have a longer service life compared to the equivalent gasoline version, as there is less heat involved. The actual diesel block is also much more rigid than a gasoline equivalent. There are no spark plugs to replace when it comes to servicing, and the service intervals are generally longer. But...

Diesel engine require more expertise. They require good quality oil, and the injectors are a lot more expensive than gasoline ones when they go wrong. Unlike gasoline injectors, they are calibrated cylinder-specific. Mix them up, and you'll have to set the injection volume. This requires dedicated OBD software.

Leaking diesel injectors will dilute the engine oil, if the oil level rises too high, it will get sucked up into the intake. This will cause the engine to rev unchecked, past the speed governor in the diesel injection pump. You won't be able to stop it, not even if you switch off the ignition. If you have the presence of mind to shove the gearshift into 5th, and dump the clutch, you can stall the engine. Otherwise, the engine will simply rev itself to destruction.

Later diesel engines from approx. 2007 have a DPF (Diesel Particulate Filter) as part of the exhaust system. They need to be really hot to be efficient. If you only cover short trips, forget about buying a modern diesel-engined Mercedes-Benz. The DPF will seldom reach optimum operating temperature, and will eventually become clogged with soot, engine performance will drop off, and fuel consumption will increase. If you're lucky, a 30 mile drive at 4000 rpm in 3rd gear may clear the soot blockage. If you're unlucky, it won't, and a replacement DPF will be your only option.

If you mostly do highway speeds on a regular basis, and cover over 10,000 miles per annum, the diesel-engined Mercedes-Benz is ideal - it'll eat up the miles effortlessly, it will return up to 58 mpg in the C-Class, it has immense pulling power, making its maximum torque from as low as 2000 rpm. The extra weight of the diesel engine up front will be evident, though with RWD it shouldn't be an issue. The 2.0 common-rail turbo diesel is best matched with automatic transmission, for smooth, and seamless performance.

If you do lots of city driving, and cover less than 10,000 miles per annum, you're best off with a gasoline-engined Mercedes-Benz. Or at least a pre-DPF diesel, meaning no newer than 2006.

Good luck!

Wadoooo Bros
always respect.......

sheffyUTD:
I have asked this question on the benz forum but seems the thread has shifted base to WhatsApp.

I never knew there's a diesel engine for Mercedes car c-class until I saw a 2003 c220 cdi. I was curious and wondered what they're aiming to achieve with that in the small car. Compare to Gas engine, how efficient, any advantage or minus, what is the maintenance compare to petrol engine, any known specific problems for the engine, and does it requires special technical know how or anyone with mercedes experience can handle Please share your experience and let's learn.

Cc: Siena, thefakestan, amzee, ikenna351 etc.

Siena has said it all.
I concur with his/her view.