Reving car a tiny bit?

Not more that 4000

I would say stick to what your doing.. if you decided to go the 4k route you will burn a bit more fuel and if on a dead stop you drop the clutch at 4k everytime expect to buy a clutch a lot sooner. Shifting later may not solve all your problems here the car is 14 years old and if it has the original motor and clutch well over 150K possible 200K miles. The car is old and tired shifting later will only add to the stress of driving the car..

it 'will' wear on everything harder if you do it all the time .. if you plan on keeping the car a long time you should take it easy on it, it will pay off in the long run ...

Unless you have an Si, your redline is more like 6500. Still, it doesn't hurt to visit the top half of the tach now and then, and always driving like Grandma is a really good way to get your EGR system clogged up.

It's best to judge shifting yourself. If it feels 'weak' when you shift at 2500 to 3K, then go up little bit more. I used to have old 81 Subaru wagon, 4 sp, and it was kind of dog, but when I shifted into 3rd, it really had power, because the engine was revved up lots more than for other gears.

Yeah, as some said, as car is older, it might stress other parts a bit, but for god's sake, it's not gonna shake the car apart. Parts won't be falling off like raindrops!!

Hey, run some gas additive thru it few times. Clean the engine a bit, get some of the gunk out of it, it'll help with engine revving better, even at 2500-3K rpms.

So point is, if it feels weak, try shifting at around 3500, then up to 4000. There's a certain feel, thru physics when you find the correct speed to shift at. When I used to drive stick shift, I'd find the right rpms so that when I let out clutch, it actually felt like the car was picking up speed a bit. It's little tricky, but doens't mean to rev engine like crazy to get extra power and rpm. It's a fine line to find the right shifting speed to where you've got the power so engine and car don't slow down or lose power. So be careful.

But not because you might shake the car apart!! Really.....

There is definitely more power @ 4000, it won't hurt anything. Probably even more power at 5000 rpm.