[ozinaldo]

Originally Posted by robertm

Every stock 1m on a mustang dyno I've seen comes in at about 290ish. That translates well to published 340 crank HP.

Mine was exactly 294.2 whp and 342.9 wtq with questionable quality gas here (nothing like factory suggested 98 RON in Europe or its equal US 93), it was bone stock, before any kind of mod other than pedals and grills on a Mustang dyno. The dyno operator that I find as a very serious and experienced technician was confident that should read 350ish hp crank if not more (his guess was closer to 360, mine is 350 and some). Different estimations maybe compared to yours but one particular point needs to be clarified anyway: how is it possible the M3 numbers on same Mustang dynos don't match then? On the same dyno a 2012 M3 dynoed 323 hp just days before me (29 whp diference with my 1M) which I am told and have seen charts that it was consistent with previous other M3s as mine was equally consistent with previous 1Ms, and I am also reading everywhere, seeing charts since some time that stock M3s do dyno around 320 to 330 whp on Mustang dynos regularly.

Now, if we use same calculation, same ratio then the E9X M3 is doing what actually, a minimum 370 to maximum 390 hp crank? Instead of 420 ps/414 hp as advertised? I mean if we make 340, isn't it like this? At least one of these assumptions has to be wrong. I believe that there is no way a car (1M) can dyno minimum 10 % more torque than stated but at the same time makes exact same hp as advertised and nothing more. The car is obviously 5 to 10 % underrated in hp (safely speaking) and a minimum 10 % in tq. This is the only logical explanation or for a starter at least M3 guys all should go to courts and sue BMW for false advertisement!

I agree with your data which backs mine and others but can not agree with the interpretation. Unless someone shows me some proof that there is (much) more than 30 whp difference between these two cars we are talking about, that's how I tend to interpret the numbers.