My E320's performance
 

My car has a very delayed throttle response and I don't understand why.
I'm thinking my linkages may be loose or something dealing with that.
Every now and then I like to put the pedal to the metal because I get impulses and when it takes off, it takes off slowly and then when it gets to higher RPMs I can feel the speed. And i was also wondering if the Octane gas you use has anything to do with it?

Anyways its a 1996 E320, so its the only Inline 6 model, so if anyone has any input to my concerns, please put some out there for me.

I have a 1997 E320 and I experience the same thing. Unless it is a huge difference in acceleration or has changed over time I do not think you have a problem. That is simply the torque curve of the engine, the valve timing effects how quickly the engine revs. The cam opens the valves further and quicker when it hits a preset RPM, this is the rush you are feeling around 3500-4000 RPM.

This should be a smooth transition though so if you are experiencing pulses or variations up and down while at the same throttle percentage than you most likely do have a problem. Always use 91+ octane in these vehicles, that is what the engine was designed for and it helps keep everything in the engine clean.

I'm not enough of a mechanic to diagnose your problem any further, hope this helps!

Haha, wow you definitely hit it right on the spot. I forgot to mention I just replaced the wiring harness which definitely boosted it's performance. Also, Inline engines do run at higher RPMs.. am i right? Thanks for the input.