Engine Lugging at higher rpm?

Question

i have a question about engine lugging at higher rpms (if that can happen.

For example my CR-Z have an redline of 6300. If its going slightly uphill i can keep 200km/h for example in 5th gear.

But this will cause the engine to run at about 6000rpm.

When i shift to 6th gear and give full throttle, the engine will run at about 4300-4800rpm with 180-200km/h which is fine for me.

But then i am giving full throttle at an "medium" rpm, especially when going uphill the speed drops down to barely 180km/h and even less.

So the question is, which causes less wear on the engine?

Shifting into fifth, get into higher rpm but the engine can do that.

Or stay into sixth at an rate the engine is barely capable in keeping its speed (but still over 4000rpm)

Answer 1

That's not how lugging works.

Scenario: Your engine is at a low RPM (something like 500-1800, let's say) and as a consequence has slower oil flow and lower oil pressure. Under these circumstances when you dump the clutch to 6th gear and floor it, you put maximum load on the engine while it does not have adequate oil flow and pressure to maintain an oil film between all bearing surfaces. Bearing surfaces contact each other metal to metal for a few fractions of a second. That is the scenario where you are "lugging" the engine.

No engine lugging will ever happen at 4300 RPM or really anywhere in that ballpark. I mean... there's tons of engine wear going on at redline... it's just not called it lugging. Maybe *thrashing ;)