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I know I can be critical of Mercedes at times (like their absolute trashcan 9-speed transmission), but I want to give credit where credit is due: Mercedes built a really nice straight six. This engine is awesome and very comparable to BMW’s epic B58 engine. BMW can pump out well over 500 HP with their I6. I hope Mercedes can follow suit because they established a great base.
I know I can be critical of Mercedes at times (like their absolute trashcan 9-speed transmission), but I want to give credit where credit is due: Mercedes built a really nice straight six. This engine is awesome and very comparable to BMW’s epic B58 engine. BMW can pump out well over 500 HP with their I6. I hope Mercedes can follow suit because they established a great base.
Seems like the M256 so far is escaping the family cycle of unreliability. Inline 6-cylinders are rock solid foundational technology. Good to see that BMW and MB can continue with the reliable inline 6 and meet latest fuel economy and emissions regarding while delivering competitive power level.
Keep an eye on oil vapor separators and the broader PCV system - a problem on all current model German engines. Also keep an eye on bore scoring. And lastly keep an eye out for cylinder head failures like the M254 4-banger is well known for.
2023 EQE 500 SUV electric and 2024 Jaguar F-PACE SVR 5.0L
Mercedes made 48-volt "mild hybrid" part of the deal though, unlike with BMW's i6. And JLR's Ingenium i6 has an electric supercharger in addition to a twin-scroll turbo. So IMHO it's not old school enough for old farts and not high tech enough for the new kids on the block either.
I’ve owned and driven BMW’s straight sixes and Mercedes did a great job building their own. This thing is so smooth and surprisingly powerful, so long as the transmission doesn’t get in the way.
2023 EQE 500 SUV electric and 2024 Jaguar F-PACE SVR 5.0L
I'm seriously considering buying a BMW i6 right now in a Z4 because it's one of the last you can get with a manual transmission. Inline sixes are just so smooth and buttery, unlike a V8 or V10.
The M256 has NANOSLIDE (plasma) coated cylinder walls, not good. Bore scoring alert message.
The EQ-BOOST 48V hybrid system is always paired with the M256, sadly. If MB offered a car with the M256 and no EQ it would rise a few rungs on my consideration list.
Trying to trace the PCV and fuel tank vapor lines into the intake manifold. Looks like the oil-vapor separator device is integrally molded into the intake manifold. Not good, if the oil-vapor device plugs, as most of them do over time, the repair would require a new intake manifold. The manifold is not terribly expensive but the labor to do the job would be astronomical.
The M256 has NANOSLIDE (plasma) coated cylinder walls, not good. Bore scoring alert message.
The EQ-BOOST 48V hybrid system is always paired with the M256, sadly. If MB offered a car with the M256 and no EQ it would rise a few rungs on my consideration list.
Nanoslide is not the same as silitec.
From MB: NANOSLIDE is a Mercedes-Benz-patented technology that produces extremely smooth cylinder surfaces for crankcases in combustion engines. There are many benefits to NANOSLIDE. Because it is stronger, it makes the engine more reliable. The weight loss factor makes the engine more efficient and more agile. In fact, NANOSLIDE engines have been found to reduce friction by up to 50%. Really the only downfall is the obvious one; price. ANOSLIDE started as an AMG-exclusive technology. Its performance benefits make it perfect for the track because it will make an engine more powerful and help it last longer at full capacity. Today, you can’t buy a Mercedes-AMG without reaping the benefits of NANOSLIDE.
Nanoslide is a method for producing a smooth surface on the cylinder walls using twin arc spraying, while silitec is an actual coating, layed down by plasma on the cylinder walls. Similar names, but completely different. Mb disoncinued Silitec almost a decade ago, and replaced it with Nanoslide. All AMG motors use nanoslide. Baore scoring also doesn't just happen, it has to be caused by something. If you have a car without bore scoring, and maintain it well, bore scoring soouldn't be an issue. Condition cause correction confirmation.
NANOSLIDE and silitec are both garbage which lead to bore scoring.
"Twin arc spraying" and "laid down with plasma" are one and the same. Avoid the shell game marketingspeak in MB documents.
Iron cylinder liners, as used on the VAG EA839 3.0T/2.9TT hot vee V6, are best practice for scoring avoidance.
I guess you're entitled to your opinion. For me, it's like saying iron is the same as aluminum since they'e both metal. Where facts don't matter opinions reign supreme.
Funny that all AMG motors have used nanoslide and we don't see bore scoring as a problem. I'll go back to my previous post...condition cause correction confirmation. Without understanding underlying cause, there's no clear connection to cause. All the guys on this thread have cars with motors using nanoslide technology. I'm jus sayin"
More baseless scare mongering from chassis. Another day that ends in Y lol
Originally Posted by crito
Inline sixes are just so smooth and buttery, unlike a V8 or V10.
Everybody says that, but my experience is I've never driven a car with an i6 that the V8 version of the same car didn't feel smoother and more refined. That goes for both the M256 in the MBs and the B58 in BMWs.
An inline 6 is inherently perfectly balanced. A V8 requires the use of crankshaft counterweights to achieve its balance. The in-line six is also more efficient and reliable and cost effective than a V8 because it only requires half the number of valve actuation components, (cams etc)
2023 EQE 500 SUV electric and 2024 Jaguar F-PACE SVR 5.0L
Probably has more to do with the type of vehicle they put V8s in nowadays. It's either something like a Corvette where violent acceleration is the objective or something luxurious where the driver is so isolated a diesel would seem smooth. Anywho, you can definitely "feel" the smooth operation with a manual transmission like in the Z4. I would have bought this one tomorrow but some idjut ordered it without the driver assistance package:
An inline 6 is inherently perfectly balanced. A V8 requires the use of crankshaft counterweights to achieve its balance. The in-line six is also more efficient and reliable and cost effective than a V8 because it only requires half the number of valve actuation components, (cams etc)
I understand all of that, but if I was worried about being efficient and cost effective I wouldn't be driving a $140,000 S Class that loses $2,000 in value every month lol. Driving them back to back, I made it 3 blocks with the S500 and turned around and got an S580, just feels much smoother and more refined to me. Same way in the 750 vs the 760, X7 40 vs X7 60, GLS450 vs GLS580, Range Rover I6 vs V8...on and on. I just have never found an I6 compelling.
An inline 6 is inherently perfectly balanced. A V8 requires the use of crankshaft counterweights to achieve its balance. The in-line six is also more efficient and reliable and cost effective than a V8 because it only requires half the number of valve actuation components, (cams etc)
I agree. However, this is only true for other brands, but not Mbenz. Pairing a smooth engine with a less refined transmission detracts from the overall driving experience.
I generally prefer V8 engines and tend to mostly buy cars with the V8, but I am also on the same page with you that inline 6 engines are typically smoother and more balanced across most brands. My wife favors smaller, less noisy engines for her BMWs, and in most cases, those have been the inline 6 cylinders ... These engines offer smooth power delivery, reliability, and responsiveness. However, I would never consider a Mbenz with an inline 6 cylinder, simply because of their jerky and clunky transmissions. A clunky gearbox cancels out the smoothness you'd expect from an inline 6, really. This is actually one of the reasons I prefer the M278 and drivetrain in the pre-facelift W222 over the M176 in the facelift W222 or W223. The M278 "felt" sportier and paired fine with a clunky transmission... However, the M176 is too smooth to be matched with the typical Mbenz transmission. The same goes for their inline-6 engines (it just makes the case even worse).
Interesting. That helps explain why a V8 might be perceived to be more smooth. I know that years ago I had a in line six Mercedes and at idle you couldn't tell it was running. In fact one day after I had new tires installed I overheard a couple of guys sitting on a bench where I was pulling out comment to that effect. I also know that on the highway it was almost electric in it's smoothness. If you pressed on the gas all that happened is that it went faster.
I guess you're entitled to your opinion. For me, it's like saying iron is the same as aluminum since they'e both metal. Where facts don't matter opinions reign supreme.
Funny that all AMG motors have used nanoslide and we don't see bore scoring as a problem. I'll go back to my previous post...condition cause correction confirmation. Without understanding underlying cause, there's no clear connection to cause. All the guys on this thread have cars with motors using nanoslide technology. I'm jus sayin"
Dear Sir,
Are you stating that silitec and NANOSLIDE are the same, or that they are different?
I agree. However, this is only true for other brands, but not Mbenz. Pairing a smooth engine with a less refined transmission detracts from the overall driving experience.
I generally prefer V8 engines and tend to mostly buy cars with the V8, but I am also on the same page with you that inline 6 engines are typically smoother and more balanced across most brands. My wife favors smaller, less noisy engines for her BMWs, and in most cases, those have been the inline 6 cylinders ... These engines offer smooth power delivery, reliability, and responsiveness. However, I would never consider a Mbenz with an inline 6 cylinder, simply because of their jerky and clunky transmissions. A clunky gearbox cancels out the smoothness you'd expect from an inline 6, really. This is actually one of the reasons I prefer the M278 and drivetrain in the pre-facelift W222 over the M176 in the facelift W222 or W223. The M278 "felt" sportier and paired fine with a clunky transmission... However, the M176 is too smooth to be matched with the typical Mbenz transmission. The same goes for their inline-6 engines (it just makes the case even worse).
I drove a 2021 S500 for around 2 months. It was a dealer loaner...long story around that for another post. But I never thought the motor and transmission felt clunky in operation. I thought the brakes were clunky; the integration of the regen with the mechanical braking force was unsettling, and I never got used to it. One thing to note, as MB uses hybrid drive to smooth out the deficiencies of ICE motors, I think a lot of issues with smoothness will be removed. 10+ year old technology, and the experiences related to them, will shortly be a moot point. I will, however, concede that at idle, the Straight 6 wasn't nearly as smooth as the V8 in either of my W222 cars. I guess inline motors don't have the balance of V6's, based on what you and @MBNUT1 are saying.
Actually the point I was making was that in line six's are perfectly balanced which is why you and SW20S's experience with the S500 curious.
O, gotcha. Maybe what I felt at idle in the W223 S500 was due to exhaust noise. The car drove super smooth and quiet, especially with those tires with the foam inside
Last edited by carlosinseattle; 08-12-2024 at 07:29 PM.
O, gotcha. Maybe what I felt at idle in the W223 S500 was due to exhause noise. The car drove super smooth and quiet, especially with those tires with the foam inside
Makes sense. For sure the six is going to have to work harder than the V8 to move that mass.