Home » Mercedes-AMG Lops Half The Cylinders Off Of The SL

Mercedes-AMG Lops Half The Cylinders Off Of The SL

The rear 3/4 of the Mercedes-AMG SL 43

Mercedes is slicing cylinders, the Chevrolet Bolt is back, news on your favorite Vietnamese automaker. All this and more in today’s Morning Dump.

Welcome to The Morning Dump, bite-sized stories corralled into a single article for your morning perusal. If your morning coffee’s working a little too well, pull up a throne and have a gander at the best of the rest of yesterday.


2023 Mercedes-AMG SL 43 front 3/4
Photo credit: Mercedes-Benz

We all kind of knew this was coming, didn’t we? After Mercedes-AMG’s announcement that the next C63 would be missing half its cylinders, it shouldn’t be surprising that engine downsizing would apply its grip to more models across the AMG range. The latest four-cylinder AMG is the entry-level trim of the SL 2+2 roadster, marking the first time that an SL has featured a four-cylinder engine since the 190 SL of the late ‘50s and early ‘60s. More specifically, the Mercedes-AMG SL 43 uses Merc’s M139 four-cylinder engine in a 381-horsepower (280 kW) state of tune. Hey, 381 horsepower isn’t objectively bad no matter how you slice it. This particular M139 variant also uses an electric exhaust gas turbocharger, the first application of that tech in a production car. What’s an electric exhaust gas turbocharger? It’s a turbocharger with an electric motor sandwiched between the turbine on the exhaust side and the compressor on the intake side. Powered using the car’s 48-volt electrical system, it should theoretically reduce turbo lag.

While the M139 is a fantastic four-cylinder engine, I do have some concerns. Although the electric turbocharger on the SL 43 should theoretically help mitigate the lag that plagues the CLA 45, it is a rather peaky engine. Maximum torque of 354 pound-feet (480 Nm) doesn’t hit until 3,250 RPM, nearly halfway up the rev range. A high-strung four-cylinder fits great with the super leicht definition of the SL nameplate, but no SL since the Gullwing has really been super leicht. They’re boulevard cruisers, made to waft very serious businesspeople from Los Angeles to Palm Springs. The sort of people who were raised in an era when six-cylinder engines were considered small, let alone four-cylinder engines. A peaky engine doesn’t really waft, nor does it offer subdued NVH characteristics appropriate for luxurious highway overtaking. Needless to say, it’ll be interesting to see what gearing and NVH reduction methods Mercedes-AMG is using in an attempt to maintain the SL’s plush nature.

The Bolt Is Back In Town

The GM Orion Assembly Plant
Photo credit: General Motors

After seven long months of shutdown, the Chevrolet Bolt and Chevrolet Bolt EUV are back in production. At $32,495 including a $995 destination charge, the Bolt EV is really cheap for a long-range EV, and cheap is generally a good thing. Like most people, I don’t make six figures or live in a paid-off house, so any EV with an MSRP under $35,000 is a win for me. While some consumers may be wary of the Bolt following the LG battery recall, the new battery packs feature a modified design and seem to have fixed the old car’s self-immolation problem.

Not only is the production restart good news for bargain-hunters looking for a brand new daily driver, it’s also good news for employment at GM’s Orion Assembly plant in Lake Orion, Michigan. Between the restart of Bolt production and the announcement of expansion to build the 2024 Silverado EV, GM created 100 new jobs in Lake Orion just last month with thousands more on the way. More jobs for the rust belt always seems like a nice thing.

Toyota Breaks Out The Cameras

An autonomous Lexus LS
Photo credit: Toyota

In the relentless pursuit of autonomy, Toyota’s Woven Planet unit is taking a non-traditional approach to data collection. Instead of slapping LIDAR on a handful of test vehicles, Woven Planet is using a ton of cameras to collect vision-only data. On the face of it, camera data seems sub-optimal to LIDAR, but Woven Planet says that the majority of camera data has increased its system’s aptitude by similar increments as LIDAR data. Not bad at all considering a camera setup is 90 percent cheaper than Woven Planet’s typical sensor array.

While this sounds similar to what Tesla is doing with its FSD Beta program, there’s a huge difference in the implementation here. Woven Planet is only using cameras for training data collection – their actual automated vehicles will be equipped with LIDAR and radar for superior performance over camera-based systems. Michael Benisch, Woven Planet’s vice president of Engineering, thinks that safe camera-based autonomous systems are still many years out. In an interview with Reuters, Benisch said, “The question may be more about when and how long it will take to reach a level of safety and reliability. I don’t believe we know that yet.”

Vinfast Takes Things Public

VinFast VF8 front 3/4 shot
Photo credit: VinFast

Hot on the heels of its factory announcement in North Carolina, Vietnamese electric carmaker VinFast has confidentially filed for Initial Public Offering. The EV maker’s parent company, Vingroup JSC, has taken the first step towards going public by registering with the U.S. Securities and Exchange Commission. Although the size of the offering hasn’t officially been decided yet, Bloomberg expects this IPO to raise approximately $2 billion which would make this the biggest IPO ever from a Vietnamese company. In addition, VinFast is looking at a potential pre-IPO funding round of between $500 million and $1 billion.

I have a good feeling about VinFast. Unlike most EV startups, they actually have products on sale. Their VF e34 subcompact crossover has been in production since December 2021 and saw 25,000 pre-orders from the Vietnamese market. What’s more, VinFast isn’t taking the popular route of merging with a special purpose acquisition company. Marching through the front door with an IPO requires a wider scope of financial diligence and proper underwriting, so VinFast’s bills are likely all in order. While pricing for the VF8 and VF9 mid-size and full-size crossovers seems a touch high considering we don’t yet know what the battery leasing costs will be, it’s more than likely that these Pininfarina-designed family haulers will actually come to market.

The Flush

Whelp, time to drop the lid on this edition of The Morning Dump. Give it up for Thursday, Friday’s little brother. As we march closer to the weekend, I’d love to know how you feel about battery leasing. While there’s definitely an appeal to leasing an EV if you own a small business and can take a write off, people who like to buy cars typically like to buy the whole car. Personally, a battery leasing program would have to be really cheap for me to consider it. As a renter with no overnight Level 2 charger access, DC fast charging is expensive and a battery lease could push EV running costs close to those of a combustion-engine car.

Lead photo credit: Mercedes-Benz

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22 Responses

  1. The SL really needs a full rework. I am less and less excited about any of the modern ones as time goes by and I want a pagoda more and more. Mercedes really has the wherewithal to put out something that competes effectively with the Boxster or Cayman. When it comes to open top, sporty motoring in the luxury category, I struggle with really spending my imaginary money on anything other than an imaginary Porsche.

    1. The amount of money being poured into silicon carbide and gallium nitride power electronics is staggering.

      Disclaimer: a division of my company is one of the world leaders in the space, so I may be overly appreciative.

      1. …crawling out of sewer, reaching, yearning, pushing up on the manhole cover to get a sweet breathe of fresh air

        …checking phone

        …David Tracy had all this information years ago. Why did I just waste my time?

  2. I’ve driven a V8 with 390hp, and a V6 with 470- the V8 was a better, smoother engine.

    I get it, we can’t have 6.0 fire-breathing V8s anymore, but there truly is no replacement for displacement.

    1. If they’d drop that 6.0 V8 into a featherweight streamliner with long-legged gearing, fuel economy could approach or exceed that of a 4-cylinder with typical weight and drag. All one needs to do to demonstrate this theoretically is a BSFC curve of each engine and some basic math, to then compare two hypothetical cars, one 6.0 V8 with a CdA of 0.3 m^2 and a mass of 1000 kg, and the other a 1.5L L4 with a CdA of 0.6 m^2 and a mass of 1800 kg. Assuming both are using modern engine technology, I’d wager the V8 car would get better fuel economy than the inline-4.

      The main issue with the V8 is pumping losses when idling, and the fact that all ICE engines see their thermal efficiency decrease as percentage of max load decreases. This is why small-displacement, power-starved engines tend to get better fuel economy than large, powerful engines. But the difference is not as large as one would think. Compare the 1989 Mustangs, the 2.3L L4 and the 5.0L V8 on fuel economy. The 5.0 V8 gets 15 City, 23 Highway, whereas the 4-cylinder gets 18 City, 24 Highway. Not a huge difference. Most fuel consumption is the result of load: wind resistance, mass, and rolling resistance.

      If I had the funds, I think building a midsized 5-seater RWD streamliner with a 0.15 drag coefficient and 2 m^2 frontal area would be fun. Keeping the weight reasonable, around 1200 kg, with a modern LS8 V8, the math suggests about 45 mpg @ 70 mph highway steady state cruising is possible.

      1. “….compare two hypothetical cars, one 6.0 V8 with a CdA of 0.3 m^2 and a mass of 1000 kg, and the other a 1.5L L4 with a CdA of 0.6 m^2 and a mass of 1800 kg.”

        I think you set a record for the amount of numbers in a sentence. Even after typing out word two and one.

    2. The smoothness is more a function of the number of cylinders as the ignition happens at a higher frequency than 6 or 4 cylinders and thus feels smoother. This is also why V10s, V12s, etc, are typically smoother and sound smoother than V8s.

      There are many more variables revolving around engine smoothness, but displacement is not typically something that helps it.

  3. I would lease a battery. Think of all the Leafs that are functionally worthless because their batteries conked out, despite the rest of the car being perfectly fine.
    As long as the R&D pace for them stays frenetic, batteries really seem like the one aspect of future car ownership that make sense to turn into a lease or subscription. Subscriptions for infotainment or hardware that won’t get any better over time? That’s corporate cynicism and greed, and it deserves to be shamed relentlessly. But batteries, which keep improving and can keep an EV on the road practically forever with replacement? I’d subscribe to that.

    1. Great idea. Or even just offer a core deposit baked into the MSRP that gets you most of the way towards the newest battery, whenever you decide to swap up.

  4. “the Bolt EV is really cheap for a long-range EV”

    Yikes, we have different definitions of long range for sure. The Bolt offers decent range for the money, but is no longer anything I would consider long range by any stretch.

  5. I legit did a spit-take when I realized you were naming your daily news brief Morning Dump. Just perfect. I love this site. I’ll never look back (you know where).

  6. The battery seems to be the weak spot of any EV, so I would have no issue in leasing a battery if it allows its manufacturer to hold the bag if it doesn’t last a normal service life and necessitates a replacement. It would make Leafs more attractive if they could be restored with a bright and sparky new power source!

  7. The local Chevy dealer has one facelift Bolt EV and three EUVs from before the stop-sale. On my weekly trawl of the car dealerships I noticed a SOLD sign on one of the EUVs. I’m certain it won’t be that long for the others.

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