The dyno is about how they perform up to 5k rpms and the truth is not too far off from that post - the 540i and the m5, on a dyno, look very very similar up to 5000 rpms. That is why a 540i with an m5-equivalent rear diff gearing feels almost identical from a butt dyno perspective.
I don't know why this is a surprise to anyone...despite having an extra half liter of displacement, the s62 is setup to be a bit more of a high horsepower screamer. The ITBs and alot of the other differences between the m62 and s62 are about responsiveness and agility of the engine, but that doesn't show up on a dyno.
There is a fine case to be made about why some people should own a 540i instead of an m5, depending on their needs. I fit the bill, given the amount of driving I do. However, I wanted everything the m5 had to offer in addition to the engine.
So I say, no, ,this isn't put to bed, it's pretty close to reality. Don't forget too that the 540i has a modest, but meaningful, weight advantage as well.
it's an anemic M5 if it is one, at all. where's the torque graph?
314whp compared to 261hp (@ their peaks) doesn't quite add up.
Agree, that is the by far the healthiest 540 and the unhealthiest M5 engine outputs I have ever seen.
Stock 540 is 282. So using the 15% drivetrain loss as we use for the M5, that puts PEAK rwhp at about 240, vs most M5's about 325-330. So the 540 is overstated by 20 rwhp and the M5 is understated by 20 rwhp at maximum. A 40 rwhp difference.
I recognize the shape of the hp curve may be different and the 540 runs closer to the M5 below about 4500- 5000 rpm, but the numbers are still a bit off.
Depending on year 540 is rated as much as 298hp even though all vanos are identical. Maybe it was a software update? The 540 factory press numbers are generally considered low because they typically run 260 at the wheels in stock form.
For the youtube comparison comment, i figured he meant find a youtube of them drag racing which is far more likely to be posted than dyno runs.