OK, I lied because I am back at this thread. After a little research, I would like to offer a few more comments.
The link Ross offered (http://www.daimlerchrysler.de/class...e/content_e.htm
) was not for a production engine. Only eight (8) were made and it was not for sale. There are so many race engines so it is hard to compare.
Let's try to compare oranges with oranges. In this case, production engines that are naturally aspirated. One can walk into a dealership and actually buy one.
The engine in the 190E Evo II was a eurospecs 4 cyl, 16 valve 2.5 and not available in the US. The street version produced 235hp.
OK, that is about 94 HP/L. A great engine, indeed.
I searched MBUSA's Website and found the highest output (displacement normalized), naturally aspirated engine is the AMG 32 used in the C-class and SLK. Here are the specs:
AMG-built intercooled supercharged 3,199-cc SOHC V6 Engine. Net power 349 hp.
That is about 109 HP/L. It is even greater than the 190E Evo II. A great engine.
Somehow I always thought Honda makes great engines so I took a look at its Website and I found this:
The 2.0 liter engine on the Honda S2000 produces 240HP. That's an amazing 120-HP per liter, the highest specific output of any normally aspirated production engine in the world.
That is a bout 120 HP/L, higher than the Mercedes-Benz AMG engine, much higher than the 190E Evo II.
I am sure there are other manufactures that are producing similar engines.
Point of mine is that Mercedes engines are good (or should I say AMG in this case) but I will never blindly say they are always the best. They are good. Every manufacture has access to the same advanced manufaturing/material/design technology so should be capable of producing great engines with no leaky head gaskets, no frying MAS and wiring harness.