Stereo ratings on watts are kinda like horespower figures.
25 watts peak is almost like saying "at the crank"
Most headunits that claim that kind of power (I don't think the Lancer has an outboard amp, so the power must be coming from the head) are quoting peak figures, just like 90% of the industry. If you went to a stereo shop and looked at a high quality 25x4 amp (as in Rockford Fosgate, Kenwood, SOny, Pioneer, etc.) you would see a device much larger then any headunit. If you think they can pack the electronics necessary to produce the same power as a separate power amp, then you were fooling yourself to begin with. That's why the speakers distort quickly when you turn it up, the head doesn't have enough reserve. It can peak at 25 per channel, but not exceed it. Music has a lot of transients, peaks and valleys. A separate amp may produce 25 per channel RMS, but peak a lot higher, thus less distortion when the bass hits. You wouldn't want a car at which whose top speed is 55-70 mph, even though that's the highest legal speed, you'd want one with reserves to accelerate out of harms way when merging, and not feel all loud and wound out at the top end. Hope this helps.

 

Wouldn't it be closer to HP or torque at a certain RPM moreso than wheel/crank?

Like you can get 120hp at 5500rpms like you can get 25 watts peak, but the majority of the time you're not making that power? I dunno. Seemed like a better analogy to me.

 

I said it before and I'll say it for the 3rd time the stock speakers sound great if they're amplified. I can't say anything about how they sound off the stock stereo because I never heard the stock one since I removed it immediately upon purchasing my car.

 

That is true, that analogy does work better in most cases, yet here is where both analogies fail. When you've got your stereo cranked, the quality of the watts being put out tends to suffer at the "redline" so to speak. Distortion tends to rise and the amp to starts to clip (the top and bottom of the waveform gets shaved off to attempt to produce the volume level desired) and the sound gets worse, possibly damaging your speakers. HP quality doesn't fall at redline. A bigger amp has more head room and generally sounds better at the same level then a smaller amp nearer its peak. Lonee's right, a better/bigger amp might be all the typical stereo owner needs to get great sound out of the stock system, that and a small (10") woofer to take care of the lows that the speakers can't reach. A good 4ch amp 4x25 to 50, if you don't want/need a fader, with the front two channels running the four in car speakers (in an OZ) and the back two bridged into a sub would be a great first upgrade.

 

didn't mitsu promise an actual bult in subwoofer?

 

It is always better to overpower speakers than under power them.
Distortion is caused when a low power amplifier tries to push too hard.
This is the reason the head unit might distort the sound, but an aftermarket amp will make them sound good.
The amp or head unit at least should be the first thing upgraded, then the speakers.
If you were to do speakers first you could really damage them.