Although an M3 is a very attractive car, its fuel economy is kryptonite for me. A car means freedom of motion to me first, and that means freedom from the cost of driving at a whim. I don't like the poor fuel economy of the V8 M3 - a car specifically designed to beat 911's in competition after they were unable to do it using 6 cylinders. Anyone can design a car that can go faster and even handle but not get good fuel economy. For all its flaws, Porsche always improves power AND fuel economy in its design upgrades.
Diesels hold a special place in Europe and they do outperform gassers, in general, under most circumstances. 0-60 times be damned. To each his own. You talk HP, but you drive torque.
And I won't be fooled to think that ANY M3 owner thinks he/she doesn't feel their car is FASTER than yours. So don't give us 335d owners that BS about us being jealous because we know you think you are faster. Perhaps. You are certainly paying for it.