The Mercedes M256 Engine Manual. Mercedes has a reputation for producing high-performance turbocharged engines. Mercedes-Benz may be regarded exclusively as a luxury brand by some. However, given the adaptability of many engines over the manufacturer’s history, this can be a limiting viewpoint. The Mercedes M256 engine is a straight-six turbocharged engine that replaced the M276 V6 engine. The M256 is part of the Mercedes modular engine family, which also includes the four-cylinder M260 and M264, as well as the OM656 and OM64 diesel engines. The Mercedes M256 3.0 liter engine was released in 2017 and is progressively being used in various vehicles. However, the majority of these vehicles will be on the pricier side of the range for Mercedes’ uses. Drivers should expect a premium price tag, even by Mercedes-Benz norms, with luxury and performance as top objectives.
The M256 is a block engine made of aluminum alloy with dual overhead camshafts and a twin-scroll turbocharger. The power output of these four-stroke inline-six turbocharged engines is outstanding, with 362-429 horsepower and 369-384 lb. ft. of torque. It’s also worth noting that direct-injected engines are notorious for requiring meticulous maintenance and the use of high-quality oil in order to achieve higher mileage. Unfortunately, the M256s are still young enough that statistics on typical faults are difficult to come by. However, in this post, we will identify and investigate some of the most likely faults in the M256, as well as discuss general reliability, diverse applications, cost, and engine specs.
With that said, let’s have a look at the fundamental engine specs for the Mercedes M256 in the section below.
Mercedes M256 Engine Specifications
The following are the basic engine specifications for the Mercedes M256:
The Mercedes M256 engine prioritizes luxury and power, with horsepower ranging from 362-492 depending on application. Aluminum blocks and heads are extensively used in modern engines to reduce weight while increasing power and performance. In fact, the M256’s cylinder heads are built of a contemporary aluminum-silicon alloy, allowing for even more weight savings. A newly designed integrated starter-alternator increases power while also reducing size and weight by replacing belt drives that operate the air conditioning and water pump. Finally, the Mercedes M256 employs a twin-scroll turbocharger with an insulated exhaust manifold and an electric auxiliary compressor to aid in the reduction of turbo lag. The light-hybrid integrated system helps balance the M256 engine’s capabilities while significantly increasing power, an intriguing adaption that we will look at more below.
Mercedes hasn’t produced an inline-six engine in quite some time. Check out our earlier guide on the Mercedes M104 engine for more information on Mercedes’ last inline-six. Mercedes expects that the new M256 engine will uphold the brand’s performance standards and boost overall reliability while still delivering a versatile engine that can be used in a variety of vehicles. thus, let’s take a look at all of the numerous cars that have used the Mercedes M256 engine thus far.
Applications for the M256 Engine
Mercedes has progressively increased the number of uses for the M256 engine, which was first offered in the 2017 S-Class W222 S450 and S500 models. Unfortunately, many of the models listed here are only available in the European or Asian vehicle markets. The list of models that use the Mercedes M256 engine is provided below.
M256 E30 DEH LA GR: M256 E30 DEH LA GR:
- S450 & S450 4MATIC W222
- CLS 450 & CLS 450 4MATIC C257
- AMG GT 43 / GT 43 4MATIC+ X290 AMG
- GLE 450 4MATIC V167
- GLS 450 4MATIC X167
- PHEV Austro Daimler Bergmeister
- 4MATIC W213 E 450
- 4MATIC W223 S 450
- 4MATIC W223 S 580
M256 E30 LA G DEH
- W222 S 500
- E53 W213 4MATIC+
- 4MATIC+ C257 CLS 53
- AMG GT 53 4MATIC X290 AMG
- GLE 53 4MATIC V167
- S 500 4MATIC W223
- Straight-Six Aston Martin DBX
The power output of the G and GR engine variants differs. The G variant has 429 horsepower and 369 pound-feet of torque, while the GR variant has 362 horsepower and 384 pound-feet of torque. Because of the novel incorporation of a light-hybrid system, these inline-six engines may produce significant power, which we shall explain further below.
Many of these models will be quite expensive. The standard S-500 sedan, for example, starts at $110,000. All of the models listed above are produced beginning in 2017 and continuing through this year’s 2022 modifications. In conclusion, let’s take a closer look at the engine design and the whole driving experience of the vehicles that use the Mercedes M256 engine in the following part.
Design of the M256 Engine and Driving Experience
The Mercedes M256 engine is related to the M260, M264, OM656 Diesel, and OM64 Diesel engines. The engine employs the previously mentioned aluminum blockhead, as well as twin overhead camshafts with four valves per cylinder. Surprisingly, the M256 employs a 48V “light-hybrid” technology. The integrated ISG 48V light hybrid system contributes to the overall power of the engine. 430 horsepower from an inline-six engine is quite outstanding, and the M256 can attribute this to the light hybrid integration.
But, is the M256’s power being used effectively? Is the driving experience satisfying enough for real enthusiasts? Unfortunately, the quick answer is: no, it does not. Despite the current power and performance data that Mercedes offers, many M256 engines are still used in vehicles that feel cumbersome or boat-like. Of course, some drivers will argue that these engines are vastly superior to Mercedes’ earlier high-power offerings. Nonetheless, it is widely stated that these linked vehicles continue to prioritize luxury over a high-quality driving experience. However, it’s difficult to fault an inline-six engine with this much power. Unfortunately, some of the costly large-bodied models to which the M256 has been applied are easy to condemn.
Mercedes M256 Engine Reliability and Issues
Because the M256 engine was debuted in 2017, numerous difficulties and issues have yet to be resolved. Direct injection engines, on the other hand, necessitate careful maintenance and prompt repairs in the event of a problem. High-quality oil is also required for the M256 engine to achieve increased mileage and maintain its everyday dependability. Modern high-performance Mercedes engines are notorious for being difficult to maintain and repair. Due to the cost of replacement parts and different labor rates, drivers may face greater repair costs when compared to similarly-sized engine types on the current automotive market. Mercedes is actively attempting to improve its reputation in terms of dependability and durability. Long renowned for being expensive to maintain and requiring periodic maintenance (particularly at higher mileage), let’s hope the newer Mercedes M256 engine benefits the brand by being a long-lasting engine.
Overheating is one of the first issues that drivers have reported with the Mercedes M256. Unfortunately, Mercedes’ only remedy is to return to the dealership and upgrade the 48v light hybrid system via the CPU. Fortunately, this appears to correct many of the overheating and engine light issues that M256 drivers are facing. In addition, several drivers report intermittent problems with smaller electronic and lighting components.
We intend to provide an accompanying guide as soon as additional data on dependability and difficulties with the Mercedes M256 engine is collected. Meanwhile, for more in-depth information about the Mercedes M256 engine’s predecessor, see our page on the most common Mercedes M276 engine problems. Mercedes attempted to address many of the shortcomings or defects in the M276 engine, but no model is flawless, and Mercedes’ isn’t often linked with long-term everyday reliability.
Related : The Mercedes M104 Engine Manual
Summary of the Mercedes M256 Engine Guide
When Mercedes announced the arrival of a new inline-six engine, Mercedes enthusiasts’ ears perked up. The M256 engine, as well as its predecessor, the M104, are gradually replacing the M276 V6 engine in Mercedes’ applications. There are no obvious design problems in this direct-injected engine. However, we anticipate hearing about more prevalent issues as time and mileage pass. Mercedes-Benz continues to gain durability recognition in the aim of eradicating some of its history’s chronic dependability concerns and pricey repair problems. However, it is clear that the Mercedes M256 engine requires regular maintenance and repairs in order to maintain its longevity and power production.
Unfortunately, many of the M256 engine’s uses will be in some of Mercedes’ more expensive cars. Many of them will not even be available in the United States. However, given that Mercedes has installed the M256 engine in these higher-priced models, it is apparent that the firm is optimistic about the M256’s future. However, Mercedes-Benz appears to struggle with blending performance and luxury with pricing, or perhaps they simply do not care. It’s simple to appeal to a consumer group that values appearance and reputation over performance and value. That doesn’t mean the M256’s power and performance are overhyped, but it does imply that the price points do not reflect the entire value.