M5 V8 Pros:
- torque
- hp
- torque

M5 V8 Cons:
- weight. It's funny, it seems that the same people complaining about understeer want a V8. What do they expect with a heavier front end? Oversteer? Duh. Going to be hard to match BMWs prized 50/50 weight dist. even with heavier trans, diff, suspension and exaust, making the whole car heavier. Again it seems some folks bitching about the car being too heavy are also complaining that there's no V8, which will just make the car heavier.

- displacement _can_ make up for emissions, but this is not the case with M5 V8.

- torque is probably too much for the chassis or suspension. You Ideally, you want a flat torque curve that gives you just enough to break the tires loose at any speed. Any more than that is a waste as you're just spinning the wheels getting no place fast. Now since we are far from ideal, we live with too much torque in some rpm so that we still get enough torque at other RPM. But BMW made a big do about the new I6 matching the chassis.

- Shorter RPM range. Again, BMW made a big deal of the wide usable RPM range. You'd give that up with the M5 V8. You could change the gearing I guess but is that buying you a whole lot?

It cracks me up to hear people say over and over that M3 is about handling and then hear complaints about no V8. You want a heavier performance car with V8 power? It already exists and it's called an M5! Go buy an M5 and put 3 series emblems on it if that's what makes you happy!

Now in theory BMW could pull a smaller displacement V engine out of nowhere that's both lighter and more power. But you'd think we'd have heard about such a development by now.

As far as BMW needing a V8 to compete in various GT series... they're doing fine and are closely matched from what I can tell. Putting in an M5 V8 would likely bump them right out of the current class and they'd loose their handling advantage as well. If they wanted to complete with the classes above (turbos) they could certainly do one themselves and they often did in race series long ago. BMW may try to homologate some new tech but I don't think an M5 V8 in a 3 series chassis will be one of them.

Now if in a year or two I'm proven wrong and you're all driving your V8 M3s here in North America, laughing at me in my Skoda, I'll gladly eat my words. Pass the alpha-ghetti and tobasco sauce please. But please don't force me to listen to stuff like "why does my V8 M3 push / understeer" and "why is V8 M3 so heavy" and "V8 burned my M3 clutch / diff again"