Its because the E90-E93 engines are not running currently at their full potential. BMW, more than likely because of having a 3 series car and their new baby, the V-8 M3, running with the same power, underpowered the car a lil bit.
Plus, coming from the turbo world before, when you have a car with an engine thats already turbocharged, mods and the potential for a really powerful car are there more so than a naturally aspirated vehicle.
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2007 E92 Montego Blue 335i
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