Our E300 regularly sees 5000 rpm. Runs great and with 4-valves per cylinder, it was clearly designed for high rpm use.

__________________
'98 E300 turbodiesel

I often run for 1-1.5 hour at 60-80, but the diesel doesn't like that sort of use any more.
The SEC on the other hand...

__________________
-Josh
Testing the cheap Mercedes axiom, one bolt at a time...

in my 84 300SD, I do an ITU every day on the way to work. Upon entering the freeway there's a hill and I get second and third to shift at ~4700 rpm. Runs great!

I, too, notice that my engine runs a little rougher after a highway run, but then settles down once I hit the streets. I thought I needed a valve adjustment. My shocks and mounts are new so I know that I'm handling the vibe mechanically. My IP dampener is the new type. The only thing I don't have dialed in yet is the IP timing. Does that have an effect on engine shake? (I'll start a new post on this, just asking.)

But is this a false economy? What toll does the ITU take on the automatic? Shifting at full throttle? Can that be 'good' for the tranny and the engine?

__________________
mjk

'84 300SD 119KMi (Liesl der Diesel)
'84 300D 326KMi when the oil left (former parts car)
'82 300SD 253KMi (new parts car)

Shifting these automatics at WOT will put extra wear on the clutches in the tranny, I believe.

A good run on the highway might cause a tight valve to grow and hence a miss that is noticable after pulling off the road. It would have been leaking on the highway too its just a lot harder to notice.

The running 80 thing depends on your local speed limits. I belive some of the western states have that as the speed limit.

In Indiana we have 70 speed limit but you can generally go ten over without danger of a ticket....not on major holidays though.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

for new members

Thanks for recycling this thread, I have done the ITU on both my mercedes cars when I bought them. My 240D was driven by a missionary in northwestern MT the furthest it had gone in 15 years was 30 miles and slowly at that. It nailed badly and idled rough; after 25 miles with my foot on the floor it idled perfectly and only nailed slightly with 385k on the clock. My 190d 2.2 runs much better after a 20 mile run at 90mph. I did not floor it through the gears as it is has an auto trans. Once I hit 4th I held it on the floor. When I let off the throttle it blew two fantastic lane filling clouds of brown and black smoke befitting of James Bond's austin martin. Now it runs much better.