The new Mercedes-AMG C 63 S E Performance didn’t exactly enjoy a rosy reception. After all, replacing a V8 muscle car in business attire with a four-cylinder plug-in hybrid was bound to ruffle some feathers. However, perhaps the most shocking part of this whole switch is that the benefits of the new powertrain seem mostly regulatory. Let me explain.
While reports of dismal sales suggest customers aren’t exactly warming to the idea of a four-cylinder C 63, concepts like feel and emotion are inherently subjective. Hard figures are less subjective, and although the old adage of “your mileage may vary” applies to fuel consumption ratings, the official figures for this plug-in hybrid are rather disappointing.
As commenter Disphenoidal pointed out the other day, the four-cylinder hybrid Mercedes-AMG C 63 S E-Performance officially gets worse fuel economy than the old V8 model if you don’t plug the new PHEV in. This seemed absurd at first, but digging into the EPA numbers, it actually checks out.
It turns out that, according to the EPA, if you don’t plug the new four-cylinder hybrid C63 S E Performance in, you could take a single combined MPG hit over the old V8-powered model. However, it seems that plugging it in will only do so much good, as the U.S. government has only rated it at one mile of all-electric range before the gasoline engine kicks in. That seems excessively low, especially compared to other jurisdictions with similar testing procedures.
Let’s look at Canada, because it uses the exact same five test cycles as the EPA. North of the border, the C 63 S E Performance is rated at 11 kilometers, or 6.83 miles, of all-electric range, and the combined gasoline fuel consumption figure stands at 11.2 L/100km, or 21 MPG. Huh, how on earth did Canada get more than six times the EPA electric-only range from the C 63 S E Performance considering that aside from default units being metric rather than imperial, Canadian-market and U.S. market cars are basically identical? EPA versus NRCAN range figures for battery electric vehicles are generally identical considering the same test cycles are used, so something weird must be going on here.
Of course, we can’t get bogged down on this electric range discrepancy alone, especially as the gasoline economy figures are pretty close between the two jurisdictions. The simple fact is that once an exceptionally short distance of battery power that probably won’t get most drivers’ commutes done runs out, losing half the cylinders hasn’t resulted in dramatic fuel economy improvement over the old V8 car. While 37 MPGe sounds great on paper, MPGe has always been a somewhat flawed metric in that it’s hard to relate to real-world use, and drivers will notice what happens at the pumps even if they can’t make sense of that headline figure. It’s also worth noting that we aren’t the only ones perplexed by the C 63 S E Performance’s plug-in range, with Motor Trend writing:
Another head-scratcher: Why does the C63 even plug in at all? Storing just 4.8kWh of electricity, the lithium-ion battery is small for a plug-in hybrid and EPA-rated for a measly 3 miles of electric range. Mercedes says the system is designed for performance rather than electric driving or efficiency, which we can confirm after plugging it in multiple times per day and managing 19 mpg-e. That matches the energy efficiency of the V-8 car hitting its 19-mpg EPA combined rating.
Admittedly, I’m not entirely sure where MT’s numbers came from given the discrepancy between them and the numbers showing up on fueleconomy.gov, but now that the dust has settled and the EPA’s called it at a maximum of one mile of all-electric range, things are even worse than we thought.
The hybrid C 63 S E Performance comes with some big tradeoffs on paper, like a curb weight of 4,850 pounds, but portliness would probably be okay to some buyers if the electric-only range were longer. However, finding a rational argument for the weight is tough with such short electric-only range and such disappointing gasoline consumption, as combining V8-like fuel consumption with EV-like curb weight doesn’t result in a logically compelling dish. Perhaps the most concrete problem with the C 63 S E Performance is that by the numbers alone, it just doesn’t seem to do plug-in hybrid things very well.
Top graphic image: Mercedes-Benz
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This is peak malicious compliance. Absolutely a waste of time, effort and money to prove a point…
What’s that sound I hear? Oh. Carl Benz rolling in his grave.
The good news is that it shouldn’t take long to fully charge the battery.
My ’19 CLS 450 had a 1kWh battery and 0 electric only range. It wasnt a plug in but still.
You know, I had another thought too. Compare the plug and battery to a nitrous kit – the battery is easy to refill basically anywhere, and you avoid the additional strain on the combustion engine that nox causes. You can get enough juice in the battery to fully power the rear electric motors for much longer when supplementing the gas engine. From that point of view it makes sense to have as small a battery as you can weight wise.
I’m not sure there’s been as much of a joke in the luxury segment since Lexus gussied up the Prius.
Funny enough that’d almost be a solid plan nowadays
This car is a disappointment on so many levels. I heard one in person the other day and it sounded like the automotive equivalent of a wet fart.
Even the notoriously generous EU test gives an EV range of 8 miles. The other huge (or is it tiny) compromise is the boot which can only hold 279l of stuff vs the standard C Class at 455l.
I can’t figure out a single reason to get this over the E53, which has the inline-6, similar performance, more space, similar cost, can be had as a wagon (in the US!), and, oh yeah, has 40 miles of electric range. It’s a wonder they sell any C63s at all, when a much better option sits right across the showroom.
671 hp vs 603 hp
The C 6 3-Dog Night edition.
Huh, and they went ahead and put a Camry dent right in the design, eh? Bold choice.
Different use case and design intent. They weren’t trying to squeeze ev miles out of this car.
Full power likely requires output from both the engine and the electric motor. They are trying to make sure full power is always on tap by keeping a high reserve.
Regen doesn’t really work for high performance driving; most energy is still loss as heat on brake. So to keep full power it can be charged between sessions.
Let’s be honest, I rarely see these on tracks, most owners just smash these around on a straight road to get a quick fix. For that, this set up gives them more acceleration while using less gas for as long as they keep the charge topped up.
Full hybrid batteries are usually only around 1.5kWh, and likely can’t output too much power. I’m not sure what typical battery discharge C-rates are for full hybrids, but the Xiaomi SU7 Ultra using CATL’s latest C-rate focused tech does 1,330kW/93.4kWh=14C peak (5.2C peak charging), while the Escape and old RAV4 PHEVs do 6.1C and 7.4C, while full hybrids seem to be ridiculous in the 60-90C range (motor kW/gross kWh). At 60C, a 1.5kWh battery could output 90kW/120hp, while a 4.8kWh pack could do 288kW/386hp, or a bit less so it can last longer than 25 seconds (FHEVs batts only have ~40% usable capacity max).
Maybe one braking zone isn’t enough to recharge the larger battery for consistent drag race runs, hence the charger? Or, with such a large battery (for a FHEV), why not add a plug as an excuse for the weight and lameness?
My thing is, with NMC batts easily crossing 200Wh/kg and so much cost and weight already invested into the motor, BMS, and electronics, why not add another 5-10kWh for only an extra 25-50kg (50-100lb) and $1-2k and easily get 20-30mi of total EPA range?
Probably can’t make anything bigger fit.
For PHEVs, the EPA runs 2 sets of tests: Charge Sustaining (how the car would operate if you never plug it in) and Charge Depleting.
For the latter, a manufacturer can calibrate the hybrid system to operate in EV mode until the battery is fully depleted. This is how most of the currently available PHEVs are calibrated, which gives them an all-electric range usually somewhere around 30-40 miles (depending on battery size and powertrain efficiency) and is beneficial for meeting CO2 regulations.
Alternatively, the manufacturer could do a sort of “blended” strategy in which the engine turns on even at high state of charge, but is heavily assisted by the hybrid system such that the battery is still actively depleting.
It seems that Mercedes has used the “blended” strategy here, which makes sense given that this is a performance vehicle – the driver would have full gasoline + electric power available at all times. No idea why they chose a different strategy for Canada vs the US though.
Just give me an AMG “Hammer”. I suspect it would still be safe and comfortable at more than modern speeds.
Compliance special or marketing mumbo-jumbo. “Plug-in Hybrid” is the buzzword of today.
I used to think PHEV’s were the best of both worlds. Then I leased one and realized its actually the worst of both.
It is the best of both worlds as you can avoid buying gasoline for local travel but have quick refueling for cross country drives. Personally have put over 3700 miles mostly electric on my phev since April or May of 2024 and still have half a tank of 93 octane left. Car runs the ice at least once a month for maintenance and lubrication, free charging on level 2 at work and cheap electricity on L1 overnight at home etc. Liked it enough to replace our other car with a second PHEV over the hybrid version of that car.
I live in France and have a 20210 Outlander PHEV. I mostly drive around town and once a week on longer trips. I am averaging about 55 mpg combined gas and electric and considering gas is close to $8 a gallon here, I am very happy. Scoff at Mitsubishi if you want, but they know how to build a PHEV vehicle. The other thing about them is they are incredibly reliable, after five years, zero issues. The reviewers looked down on them, but the reviews by actual owners tell a different story.
A lot of places in Europe are banning cars that can’t run on electricity alone from city centers. It’s why we’re seeing these incredibly stupid, over engineered German sports sedans that weigh absurd amounts and no one actually wants. It’s to exploit regulatory loopholes.
That being said if the regulations are forcing these worst of both worlds hybrid abominations that are slower, heavier, and similarly or less efficient than the V8 bruisers they’re replacing maybe they need to be reconsidered. These are going to be on buy here pay here lots for 20 grand in a few years with $30,000 repair bills that are due.
Agreed. I’ll add that the technology on this still has to work, and is moving the ball forward in terms of pushing the technology out. But around one mile of range definitely shouldn’t check the compliance box lol.
Exactly this – Mr. Moneypants (Hr. Geldenhosen?) wants to park right in the center of his clean, well-regulated European town with this. It’s short distances at low speeds so you don’t need hardly any battery.
Not to mention the interior will no doubt feature MB’s recent “strip joint” aesthetic…
Eh, they’re already getting pretty close to 20k, at least for the Grand Cherokee Hybrids.
Hold up….a 20k repair bill or a 20k Cherokee 4Xe?
$20k 4XE. The trade in values are in the mid 20’s.
I checked after I initially responded and you’re absolutely correct. There are tons of them listed within 250 miles of me in the low to mid 20s. Wranglers are a little bit more but still firmly in the 20s.
I mean…are they THAT bad? I get that some of the major car publications had issues with theirs, which can be the kiss of death (see: Giulia)…but issues or not that seems like a lot of car for that much money. I have to imagine they’ll bottom out to an extent.
Wow. I knew Stellantis’ PHEV design was pretty suboptimal for efficiency, but I thought it’d at least save some engineering cost and make repairs simpler/more conventional.
Instead they opted to make as many of the hybrid components both exorbitantly expensive and of absolute dogshit quality so they require frequent replacement
I’ll put it this way. After the number of problems I experienced I was willing to drop $10k to get out of my lease 18 months early.
Say no more lol
Yes.
Cut that used price in half, maybe people would actually bite. it’s absolutely undesireable.
now that’s a compliance vehicle!
I mean, the plug socket part of it is. Otherwise it seems legit?
It puts out 671 horsepower, 3.3 sec 0-60, and costs around 90k. That’s why someone may choose to buy one. Given the numbers here, its saving plenty of that battery so that the full 671 ponies are going to be available most all of the time. Why put a plug socket on it? Great question, its a head scratcher, but it doesn’t invalidate this as a car that does put up serious performance numbers.
I’m guessing the battery is mainly for spinning that turbo
This is exactly as stupid and cynical as I’ve come to expect from M-B these days. Nice to see they don’t disappoint.
It goes 1 miles on 4.8 kwh? They must be limiting battery usage in all electric range.
Iirc from a deep dive on the related AMG suv that shares this powertrain they retain a good portion of the battery so power delivery remains the same at all times.
I’m assuming that this was originally supposed to be a full hybrid which only uses 20-40% of its gross capacity, so that’d be 1-1.9kWh which should still be good for 2-5 miles of range at a conservative 2.5mi/kWh.
4.8 kWh? That’s a suspicious number… Oh, right- its standard modular size used everywhere from RC planes to server racks to boats. Probably about the absolute smallest you could reasonably claim is a energy source for a prime mover in an automobile application. The absolute minimum amount of fucks have been given and the answer to all of the questions posed in this article is: this POS is a compliance special. The electric drivetrain is in no way a performance enhancer, just bloat to check the legal boxes. On an AMG too.
One for the suckers. Stay far, far away.
This has the stink of “make it have a plug to qualify for some kind of PHEV incentive that HEV’s don’t qualify for” or maybe there was some planned PHEV incentive that never came to fruition that it was meant to satisfy. Not saying it’s U.S. specific, could be EU or someplace else.
Either way, having it plugged in would have the added benefit of keeping the battery in (potentially) better working order if the vehicle isn’t driven a lot.
Still dumb though.
Random side-note, I wish some OEM would make V4’s instead of inline 4’s, especially for (attainable) performance models. I know, inline 4’s make tons of sense, but V4’s can sound SO MUCH BETTER than even the best sounding inline 4’s ever made.
Interestingly, BYD and Chery have made flat-4s intended for performance PHEVs for their low CoG. So far, BYD’s F4 is in the Yangwang U7, while Chery’s was announced a few months ago and will probs hit the market by the end of the year. I’m surprised that it’s Chinese manufacturers that are bring back flat engines, though I doubt they’ll appear in too many models.
Interesting! I did not know that BYD (or others in China) were using flat 4’s.
Sounds like a V8, with an e-bike mounted on the back of the car, could be a better solution all around.
That’s called a 48V mild hybrid 🙂