Car
Car: Mercedes C43 AMG W205 (2019) – Max
Engine: 3.0 24V bi-turbo (V6) (M276E30)
Manufacturer data: 390 ch (385 hp) @ 6100 rpm – 520 Nm (384 lb.ft) @ 2500-5000 rpm
ECU: Bosch MED 17.7.3.1
Mapping (David): Ethanol conversion + slight performance optimization (Injection – Ignition adjustment)
Configuration: Stock
Fuel: Initial = UL 98 ==> Final = E85
PerfectPower Weighing
Date: Tuesday, May 13, 2025
Place: France (77)
Result: 1780 kg (3924 lb) with 1/8 of a full tank ==> 1823 kg (4019 lb) with full tank (66 L)
PerfectPower Car Sheet
Note 1: The car weight is given with a full tank (PerfectPower and manufacturer standard) and the additional weight with a 80 kg (176 lb) person on board (arbitrary standard), but these two fields must of course be systematically adapted to the real measurement conditions during each session!
Note 2: It is very rare, but we had to do a rev calibration to obtain the correct gear ratios for our power measurements (in 3rd and 4th), the manufacturer gear ratios (respectively 2.252 and 1.636) giving measured actual speeds too far from the calculated theoretical speeds (nearly 5% difference, i.e. clearly above the permitted tolerance of 2%!).
PerfectPower Results
Single session – Adjustment
Date: Tuesday, May 13, 2025
Place: France (77)
Software: PerfectPower Androïd 7.1.3
Hardware: David’s Xiaomi MI 8 + RaceBox Mini 25 Hz driven by PerfectPower
Power (I – Initial config) measurement conditions:
- Mode 2 “GPS only”
- DIN 70020 standard (engine results corrected for 1013 hPa and 20°C (29.92 in Hg and 68 °F))
- Calculation of losses on parameters (standard mode in PerfectPower)
- With 2 people on board (Cedric & David) and with 1/8 of a full tank
- In 3rd gear then in 4th gear (official) in manual mode from 2000 to 6200 rpm (rev limiter)
- With the WIXGEAR universal magnetic windshield mount even if it doesn’t matter in mode 2
- Official Result of each map tested = Average of 2 measurements performed in both directions of the road according to the strict recommendation of PerfectPower in order to eliminate the effects of road slope and wind
Accelerations (II – Semi-final config) measurement conditions:
- Mode 2 “GPS only”
- Measurement stop mode “Normal” (stop when the user slows down)
- With 2 people on board (Cedric & David) and with 3/4 of a full tank
- 25 s of acceleration to be sure of completing a 1000 m standing start (second reference acceleration after the 400 m standing start)
- With the WIXGEAR universal magnetic windshield mount even if it doesn’t matter in mode 2
- One measurement performed in direction 2 of the road, but this one is almost flat and no wind was blowing that day, which makes the times valid
Power (III – Final config) measurement conditions:
- Mode 1 “Accelerometer + GPS” (standard mode in PerfectPower) (note: we were unable to reuse mode 2 “GPS only” used before because the RaceBox battery was empty at the end of the session!)
- DIN 70020 standard (engine results corrected for 1013 hPa and 20°C (29.92 in Hg and 68 °F))
- Calculation of losses on parameters (standard mode in PerfectPower)
- With 2 people on board (Cedric & David) and with half a tank
- In 4th gear (official) in manual mode from 2000 to 6200 rpm (rev limiter)
- With the WIXGEAR universal magnetic windshield mount
- Official Result of each map tested = Average of 2 measurements performed in both directions of the road according to the strict recommendation of PerfectPower in order to eliminate the effects of road slope and wind
Note: The E85 used for this session was actually verified E80.
I) Initial config: Stock map + UL 98
1) Power in 3rd gear
Official Result = Average of the 2 measurements
Comparison of results with manufacturer data for this engine (M276E30):
- Max Power: – 6.5 ch / hp & – 1.7 %
- Max Torque: + 7.5 Nm & + 1.4 %
These results obtained in 3rd gear are superbly balanced, very close to the manufacturer data (less than 2% difference) and well distributed, with the power slightly lower and the torque slightly higher, so they can really be used as a reference!
However, the very fast acceleration rate in this gear (3rd BUT on a gearbox that has… 9!) with less than 6 s of measurement time led us to carry out all the following measurements in 4th gear, which was better for the tuning, and to use the “new” results in 4th gear as a reference for the sake of homogeneity, especially since they are directly comparable to those obtained on braked dyno where the acceleration rates are NEVER as fast as here on the road in 3rd gear with such a car!
Note: In fact, we had performed these measurements in 3rd gear a few days before the tuning session to get our bearings with this car that had just been entrusted to us, especially with these modern automatic gearboxes where it is an obstacle course to get into manual mode!
2) Power in 4th gear (official)
Official Result = Average of the 2 measurements
Comparison of results with manufacturer data for this engine (M276E30):
- Max Power: – 4.1 ch / hp & – 1.1 %
- Max Torque: + 38.7 Nm & + 7.4 %
The results in 4th gear are even closer to the manufacturer data for the max power (from 1.7 % to 1.1 %), however small surprise for the max torque which is now higher by more than… 7 %, which is higher than the tolerance margin of +- 5 % for certification of the engine results, but we will explain this further down in the comparison of the 3rd / 4th results!
3) Comparison 3rd gear / 4th gear
Official Results 3rd gear (white) / 4th gear (red)
Comparison of results in 4th gear / 3rd gear:
- Max Power: + 2.4 ch / hp & + 0.6 %
- Max Torque: + 31.2 Nm & + 5.9 % (!)
What immediately stands out is that while the results are perfectly comparable above 4500 rpm, on the other hand before this rev we note an overboost effect in 4th gear (confirmed by our engine logs), which significantly inflates the results and provides a 6% increase in max torque!
So in fact, the subject is complex because two major phenomena come into play:
- The turbo’s charge speed relative to engine speed depends on the acceleration rate: it decreases as the acceleration rate increases, and vice-versa!
- But the dynamic boost regulation strategy can also vary with the acceleration rate, but also of course with the gear engaged, for example to create an overboost in higher gears, or conversely limit torque in lower gears!
But in this case, the difference is such that we have an overboost effect in 4th gear that we do not have in 3rd gear, limited however to 4500 rpm, and as the engine results (measured in stabilized rev, but NEVER in dynamic!) are always homologated without overboost, this is why the results obtained on the road in 3rd gear are ultimately the most “realistic” if we want to compare them to the manufacturer data, BUT all this is only a question of reference since on the contrary, if you want to be able to compare them to those obtained on a braked dyno where the acceleration rates are always moderate (minimum 10 s measurement time) and where we generally measure at least on the 4th gear, then on the contrary you will have to carry out your measurements on the road in 4th gear! All this with this C43 AMG of course!
II) Semi-final config: E85 map + E85
Accelerations
Valid but unofficial result because only one measurement
Note 1: As stated in the chapter name, these results were obtained in a semi-final configuration with the map only adapted to E85, but not yet optimized for performance. We wanted to redo a measurement in the final configuration, but the measurement conditions at that time did not allow us to do so. Nevertheless, this “E85 only” map already gave interesting results with a power of 397 ch (392 hp), 11 more than the 386 measured stock with UL 98, thanks once again to the “magic power” of ethanol! Know that this level of power increase (3 %) is perfectly usual with a correct ethanol conversion, especially with supercharged engines!
Note 2: We just have a doubt about the start because we didn’t feel a strong push right away but only about a second later, which is completely confirmed by our measurement with a bad 0 to 20 km/h time for such a car, especially in four-wheel drive (1.08 s)… Cedric, who was driving, confirmed to me that he pressed fully the accelerator from the start… but normally, we should have been instantly glued to the seat from the start (which this E55 AMG does perfectly!), so we can only assume that it’s due to an extremely soft start management by the gearbox ECU in the selected mode… however, if the opportunity arises one day, we will measure the accelerations of this C43 AMG again to be sure!
III) Final config: David map + E85
1) Power in 4th gear (official)
Comparison of the 2 measurements
Official Result = Average of the 2 measurements
Comparison of results with manufacturer data for this engine (M276E30):
- Max Power: + 22.0 ch / hp & + 5.6 %
- Max Torque: + 72.0 Nm & + 13.8 %
2) BEFORE / AFTER Comparison
Official Results BEFORE (white) / AFTER (red)
Comparison of BEFORE / AFTER results:
- Max Power: + 26.1 ch / hp & + 6.8 % (!)
- Max Torque: + 33.3 Nm & + 6.0 % (!)
This comparison is simply amazing! Indeed, the performance improvement is simply spectacular, considering that we ONLY adapted the mapping to ethanol, with just a slight performance optimization requested by Max, the owner. However, we want to emphasize that we absolutely did NOT touch the supercharging, there isn’t a single gram of extra boost (as proven by our engine logs), and it was an absolute will on our part to preserve mechanical reliability on this car, which still costs tens of thousands of euros & dollars…
No, we “only” improved combustion efficiency by taking advantage of ethanol’s properties extremely favorable to performance (and even reliability, yes!) because we at PerfectPower know better than anyone -and this since the very beginnings of ethanol- how magical this fuel is, even if -at least in Europe- it is still highly controversial in 2025 (and very surprisingly in the sports world, it’s truly the height of irony!), but anyway, the truth always comes out eventually, and we actively contribute to it at PerfectPower!
And to further illustrate the performance achieved with this C43 AMG converted to ethanol with just a slight performance optimization (and once again without touching the supercharging), know that we are almost at the level of the engine results of a Stage 1 with Unleaded 98 announced by all the remapping websites (which probably all share the same file…) at 420 ch / hp and 600 Nm: that says it all about the extraordinary performance of ethanol, doesn’t it?