revving the engine

is there any difference between revving the engine at the same rpm in different gears? as in, say your doing 20 in 2nd gear and u rev it to 5000, as opposed to revving it to 5000 in 5th gear? is the engine being used more in the 2nd gear? and plus, wat are the long term effects on an engine thats being revved up to 4000 or more regularly (in a standard car)?

It's probably harder on the engine to rev to 5000rpm in 5th as the car is pushing against more wind resistance, owing to the fact that it's going way faster.

An engine being revved to 4000 won't last as long as one revved to 3000. But we're talking maybe 150Kmi instead of 200Kmi, so it's not a huge issue. On the other hand, the 18 year old who redlines it every shift is going to need a new engine in maybe 20Kmi, so "it all depends".

Myself, I shift below 3000 unless I'm merging on to the freeway or passing on a 2-lane road, then I wrap it up to 4000 or even 5000. This is on a car with a 6000rpm redline, so I don't think I'm pushing my luck.

I had a Lada, 1500 cc, and a claimed 82 hp. (!)
If I was in a hurry, I'd run.
No, it wasn't that bad. If I was in a hurry, I'd take it to redline every shift (6500 rpm), until I got up to speed. If I wasn't in a hurry, I'd shift around 3000 rpm. The car lasted 10 years, 250,000 km. The body rotted off. The engine still worked fine, original clutch. It used about 1.5 liters of oil per oil change.

More stress on engine in higher gear at same rpm

Engine wear is exponential to rpm. An engine that only revs to 5000rpm would normally last 4 times longer than an engine that revs to 10,000rpm. That is why Formula 1 and Champ car engines are rebuilt so often. Formula 1 engines rev to 19,000rpm and often last the race duration(sometimes even fail mid race :()

that is a way too simplistic way of looking at it. It isn't based on the RPMs as much as engine wear and balance. You can run an S2000 well over a hundred thousand miles at high rpm

Basic mechanical physics, all engines being the same. Double the rpm and there is 4 times the stress(kinetic energy)

Sure, stroke/bore dfoes come into play as well as maintenance but it is a commonly accepted mechanically proven fact that engine wear is exponential to rpm. Double the rpm and suffer 4 times the wear rate.

maybe on the same engine.