Can anyone properly explain the workings of a diesel engine to everyone?

1. Torque + KW
I've noticed that on spec sheets diesel engines produce a bucketload of more torque than petrol engines. As far as I understand it, this is due to the way a diesel engine is built. Question is how do they drive?

Firstly, the KW rating is commonly lower than a similar capacity engine, however the torque rating is usually almost double or more the petrol engine. How does this equate out when driven for performance?

Say for example a 1.6L engine that makes 100KW and 160NM at 6000RPM ...

How would this compare with a 1.6 diesel that only makes say 70KW but like 220NM at 3000RPM?

I ask in terms of straightline performance and downgearing response

2. Modifications - Bolt Ons

Petrol Engines, of the naturally aspirated variety, usually carry modifications of intake, exhaust, headers (at least around here)...

is this the same for diesel engines with comparable gains?

3. Driving a Diesel

With Petrol engines, the general idea for NA is to rev it out... but for diesels peak torque arrives pretty much a little bit from idle... so when do u shift for diesel??

i hope that this thread will be useful for all