Sky1

Renntech Test Data
Is HP for the V8 the same for pre facelift R231s (2013-2016) as in the 2017x current facelift cars?
Test drove a new model, it felt the same.
MBZ says more HP in 2017 on, from same 4.7l engine.

Any thoughts/ comments?

Below test data is from Renntech public website:
[img]blob:https://mbworld.org/4a6be161-3af2-4e...6-877d81544333

Wolfman

All MB V8TT engines are underrated. MB increased the hp in 2016 before the facelift but that engine has continued to be underrated by the same amount. The facelift SL is about .2 seconds faster to 60 than the 2013-2015.

Sky1

Interesting, and I’m curious if it was a chip/reprogramming, or mechanical as it’s still a 4.7l

Perhaps someone has knowledge of what was done to the engines.

Wolfman

I don't recall on this engine but typically changes are made due for emission compliance. I assume ECU programming & boost pressure. Since the adjustments are very light, there will be no different hardware.

Keon

Renntech seems to tend to get oddly high numbers, either they are using an improperly-calibrated dyno or they simply calculate too much drivetrain loss.

whoover

Most tuners dyno higher stock numbers. It's even more extreme with the 4.0 TT. (Renntech shows 691 vs 603 published.)
https://www.renntechmercedes.com/ind...13-e63s-detail

I doubt that they don't know how to dyno a car or compute drivetrain loss. MB is very conservative in their specs. Plus, as Renntech explains, MB is citing the average over an RPM range, not the actual peak hp. They don't want to be sued for not meeting their published specs. As I said, most tuners see this. The ones with less integrity than Renntech claim their hp increases over MB's published numbers, showing huge gains where much of the improvement is merely the headroom the factory spec left them. Renntech shows a lot of class quoting their tunes' gains from 691 hp stock vs. 603.

PS. If you look at their dyno for this engine, they show the stock HP just shy of 600 hp at the wheels. I really doubt the actual AWD drivetrain loss is 3 hp.

SLclass

Another example:

Sky1

With MBZ underrating HP, and aftermarket tuners overrating HP, the actual is anyone’s guess.

All I know is this V8 is a rocket, and has phenomenal torque! It’s a lot of fun.

Quite possibly the end of the line for a non hybrid V8 with only turbo assist.

The future looks to be smaller displacement with elec motor assist, and hybrid power setups.

SLclass

BINGO!

Dr. Manhattan

Do they have a program or figures for the current 3.0TT? And, does anyone know the M designation for the V6?

Sky1

I believe you are referring to the V6 3.0TT engine in the sl450 factory rated at 362 hp/369torque. .

The engine M code is M276

There are numerous aftermarket tuners who may offer more power, I don’t have specifics.