When it comes to needing an ultra-high-performance engine off the shelf, one of the most effective ways of securing one is by knocking on the door of Mercedes-Benz. Some of the most rabid supercars in automotive history have featured powerplants sourced from the legendary German automaker, with one of the best examples being Pagani’s range of Huayra and Zonda models, which used Merc V12 units in various states of tune.
More recently, Aston Martin joined the bandwagon. Thanks to some upgrades, the engine from the Valhalla still outdoes its newer sibling.
Mercedes’ New Performance Coupe Gets A Revised M177 V8
Mythos 2027 Mercedes-AMG CLE 646 SpezialanfertigungMercedes-AMG
The M17 family of 4.0-liter twin-turbocharged V8 engines has been in circulation since the 2015 model year, with the range tending to feature in Merc’s higher-end models. The variety is all-encompassing, with variants such as the M176 being found under the hood of the GLE SUV and S-Class ultra-luxury sedan, while the uprated M177 has made the likes of the C-Class and AMG GT home. When it came to the new CLE 646 though, Mercedes decided that the standard M177 didn’t quite cut the mustard.
It opted against using the more hardcore M178 engine, which was aimed at being used in track-focused cars, and rather the M177 as it would prove more usable and refined for the road. Designated the M177 Evo, the biggest change could be found in the crankshaft, as Merc ditched the cross-plane configuration used by the standard engine, and incorporated a flat-plane layout instead. This was done to quicken up the throttle response of the engine, while also reducing the amount of rotational mass produced. This allowed the engine to rev easier, enhancing responsiveness even further.
The powerplant’s ECU software was also tweaked to unleash more outright grunt, with a revised cooling system brought along to the party to ensure this extra grunt didn’t cook the engine. The cherry on the cake was a titanium, Akrapovic-designed exhaust system, which helped the engine to breathe easier while reducing overall weight. The effects of this enhanced engine are clear, with peak power figures of 637 horsepower and 627 lb-ft of torque being made available between 2,000 and 4,500 RPM. That leaves it 190 hp clear of the CL3 53 the car is based on, which only uses a turbocharged 3.0-liter inline-six unit.
This is also 34 hp up on the standard M177 engine found in the likes of the 2026 GLE-63. It’ll also be as adaptable as its predecessor, since it has also found a home under the hood of the higher-performance GLE-63 S and S580 models, so it’s likely we’ll see plenty more of it going forward.
Aston Martin Went Much Further With Its Merc Powerplant
Aston Martin
While the gains Mercedes made with the M177 are impressive, they’re nothing when compared to what Aston Martin managed. Wanting to produce a more road-friendly supercar that sat below its track-focused Valkyrie, the British automaker wanted to find something a little more usable than the hardcore Cosworth V12 used in its flagship machine. Having supplied the bulk of its range with Merc engines for years, Aston elected to make use of this relationship once more.
It did a deal to secure the use of Merc’s M178 engine, the more hardcore variant of the M17 V8 family. The Valhalla was meant to be a very capable track racer for when its owner was in the mood for a bit of a push, before then being comfortable enough to cruise home, so this made the Jekyll-and-Hyde-like M178 the ideal engine for the job. Following a range of upgrades to the M178 unit by Aston Martin and project partner Red Bull Racing, the final unit ended up sending a commanding 817 hp to the rear axle, a figure bumped up to a Bugatti Veyron-beating 1,064 hp thanks to the addition of a hybrid system.
Thanks to a slick eight-speed gearbox helping get the grunt to the driven wheels swiftly, the Valhalla can hit 60 mph in 2.5 seconds, while its aerodynamic body allows it to reach an electronically limited top speed of 217 mph.
Aston’s Mercedes V8 Was Changed Drastically
Aston Martin Valhalla Monaco DebutAston Martin
When compared to the M177 found in the CLE 646, the Valhalla’s M178 V8 features some pretty drastic changes. Since the M178 unit is geared more towards track use than the M177, it gets a dry sump lubrication system, as opposed to the wet-sump setup found in the latter. Featuring a side-mounted oil container and pump rather than using a fixture mounted at the bottom of the powerplant, lubrication during high-speed cornering is vastly improved. In addition, the design is also lighter than the M177’s, while also allowing for the unit to be mounted lower in its host, which improves its center of gravity.
The M178’s cylinder heads are also slightly different due to the plumbing differences between both engines, but for the most part, they’re pretty similar. Aston went beyond these enhancements for the Valhalla, however. After all, even in the Mercedes AMG-GT Black Series, the engine only kicked out 724 hp, well short of the engine-only output within the Valhalla. To secure this extra 93 hp, Aston’s engineers developed new pistons and a revised camshaft, which were stronger and helped to make use of the added grunt from the hybrid system.
Larger turbos were also incorporated into the M178, while a further upgraded cooling setup and new exhaust system were also brought along, which all helped to make the 817 engine-only power figure possible. It’s not easy to make the best better, but Aston managed it with the work it carried out on the already-monstrous M178 V8 engine.
The Valhalla Needed Serious Tuning To Make Use Of The M178
Aston Martin Valhalla production versionAston Martin
Being a supercar that was meant to be accessible for its very well-off owners, the last thing Aston needed was for the car to throw them off the moment they so much as glanced at the throttle. Those lawsuits add up, you know. To get around this, it roped in Red Bull Racing, one of the most successful Formula 1 teams in the history of the sport. By doing so, it got access to Adrian Newey, the renowned British aerodynamicist and engineer who was one of the primary reasons for the Austrian energy drink giant’s racing success. Interestingly, Newey would later leave Red Bull to join Aston Martin’s own F1 operation, where he remains to this day.
Using a carbon fiber chassis, which helped keep weight low but stiffness high, the Valhalla backed this up with an advanced aerodynamic package developed by Newey and Red Bull Technologies. Using an F1-inspired flat floor that helped channel air to rear-mounted Venturi tunnels, which in-turn produced loads of downforce in conjunction with an active front splitter and rear wing, the Valhalla can produce up to 1,323 pounds of the stuff. This helps keep it stable at high speed, allowing owners to get the most from it without feeling like the machine could kill them at any second.
With so much power being sent to its rear wheels, the enhanced aero setup was crucial to making Aston’s usable supercar philosophy a reality.
If You Value Rarity, Mercedes’ New Performance Beast Is For You
Mythos 2027 Mercedes-AMG CLE 646 SpezialanfertigungMercedes-AMG
While you may expect the Valhalla to be the more special of the cars mentioned in this article, especially considering just 999 examples of the machine will be produced worldwide, you’d be wrong. The CLE 646 is a big statement from Mercedes, seeing as it brings V8 power to the C-Class-sized machines it produces. It has moved towards high-powered four- and six-cylinder engines with the lineage over the last half-decade, primarily due to emissions concerns. Thanks to public demand, the brand has started to turn its attention back to finding ways to shoehorn V8s back into its performance offerings, just like it did in the old days.
It hasn’t gone as far as to resurrect the approach to its mass-produced vehicles just yet though, with the CLE 646 set to be a heavily restricted special model. Just 30 are expected to be built, making it vastly more exclusive than the Valhalla. It’ll be jolly expensive too, since, aside from the newly developed M177 Evo V8 under the hood, the CLE 646 gets a bespoke adjustable suspension and aerodynamic package, as well as bodywork primarily fashioned from lightweight carbon fiber. It also takes advantage of Mercedes’ Ceramic Composite braking package, making it a serious track contender.
It’ll likely cost north of $1 million, if you can get your hands on one. The Valhalla will set you back around the same sort of money, so it comes down to what you prioritize the most. If you crave exclusivity, the Merc will be right up your street. If you want to go as quickly as possible with a Merc V8, the Valhalla will run rings around Mercedes’ new weapon.
Sources: Mercedes-AMG.
