The turbocharged MZR is rated at 280 lb-ft and 263 hp stock, of course there will be drive train losses. Being a turbocharged motor, you can have boost spikes where it momentarily operates outside of the original specification. Also, conditions like temperature, humidity, elevation, engine temperature, heat soak, and others can effect how much power it will make. There are also other factors, internal engine tolerances, even differences between turbos. I have seen many dyno graphs where a stock MS3 makes close to if not slightly more than 280 lb-ft, although not over the entire range (usually its a spike when the turbo builds full boost around 3k rpm.) If you would like to see some of these yourself, just search Stock Mazdaspeed3 Dyno on google. Now I will not say that every dyno of every MS3 will make 280 lb-ft, but I think you should consider that it is entirely possible that "A" stock MS3 "could" make 280 lb-ft on a dyno.
