I’m considering an ml63 2012 onwards with the sameness engine. How does this sound standard as I’ve heard mixed views. I have a 2008 cl63 and I’ve always loved the noise of that. I would presume it feels extremely torquey that engine.
The M157 5.5 biturbo engine (as fitted to the 2012 ML63) sounds fantastic, but it does so in a different way compared to the M156 6.2 in your current car (CL63). For a start it’s louder, much louder, especially when starting from cold, but the engine/exhaust can always be heard even when cruising.
It sounds husky compared to the M156, it vocal range is limited to the lower end of the scale - so it’s quite “bassy” - but it’s always accompanied with the whistle of the turbochargers when under load. It sounds mechanical, like you can hear every “bang” in the combustion cycle. Combined it sounds quite angry.
The M156 on the other hand has a very broad vocal range. It’s large capacity helps it to make deep powerful sound under load at lower engine speeds, but that changes to a roar through the mid range, and then positively sing thanks to it being such a high revving engine (relative to it’s capacity).
On balance, with a standard exhaust the M157 sounds more aggressive and so to some ears it will be more sporty. On the other hand, the M157 is quieter (especially in larger cars which have better noise insulation and isolation), and has a sweeter melodic sound, with a broad musical range.
The power delivery is different, with the M157 having more torque more of the time, which can make for a relaxing car to drive. Some say that the M156 lacks torque compared to the M113K and M157, and whilst I agree it’s more progressive, I don’t think that translates to a performance disadvantage (when standard).