I am interested in either the SL65 05-08 or the SL63 09-12.

I like the power of the 65 but I have read in some places with the lighter weight and better trans that the 63 feels almost as fast. I want to chip either one that I purchase and I know there is much more gain on the 65. I would like to know some thoughts on maintenance cost and reliability. I like the look of the 09-12 SL63 fronts. I know the 07-08 SL65 is a little better than 05 & 06. What about the SL63 any advances that make the 2012 SL63 any better?

Thank you for any help

Nelson

 

I'll post based on my personal experience only. I have driven a 2003 SL55, 2005 SL65, and 2009 SL63, which I bought. My primary background is Porsche, I was looking for something that could be a GT daily driver but still scratch my sports car itch.

My least favorite was the SL55, it's a great car but definitely felt like a German muscle car. Lots of torque down low but not very rev-happy, somewhat slow automatic gearbox, relatively sluggish turn-in, though it cornered well once it took a set. Great car but not for me.

The SL65, despite this particular car being pretty rough, blew me away. Torque everywhere, effortlessly and overwhelmingly fast, incredibly smooth, and the V12 sounds amazing (but too quiet). Incredible torque down low but liked to rev unlike the SL55. Turn in again isn't super sharp but the LSD and overwhelming power help it rotate, and the torque of the V12 helps mask the shortcomings of the 5-speed. Also hard to describe, but there's something about a V12 that just feels special.

Obviously I liked the SL63 since I bought it, of the three I'd say this is the closest to being a sports car rather than a GT. Despite being a little clunky from a stop the MCT Speedshift transmission is very very good, you get torque converter automatic comfort with the ability to bang out shifts like an F1 gearbox. I am a huge M156 fan, it has great torque down low but still rips to redline like few V8s that I've experienced. Overall responsiveness is better than the other two cars due to it being naturally aspirated. The updates made to the facelift cars were much about improving their cornering performance and it definitely makes a difference, the suspension turns in better, takes a set quicker, and has better steering feel than the other two cars. You also get the reliability advantage of improvements made to the SBC and ABC systems, which I believe were implemented in 2008. Downside is this car really needs an LSD, it turns in well but doesn't corner well under power, adding a Wavetrack or similar is on my short to-do list. If your budget permits, try to find a P030 Performance Package SL63 to get the factory LSD and sport suspension.

I didn't really touch on styling because that's totally subjective, I find the early R230 to be a prettier car but the later models to look more modern and aggressive. All of them have their own unique maintenance nuances, so do your homework in that department, to me as DIY mechanic I found that to be a wash. For me it mostly came down to budget and availability, I managed to find an excellent condition SL63 for a reasonable price that was within 4 hours of my house, getting a similar condition and mileage SL65 would have likely been another $8-$10k and required a more extensive search. Throw out that practical consideration and my favorite was the SL65. Most importantly try to drive them all, then buy what you love.

 

I was looking at some early SL65s but am happy with the decision to go with the facelift SL63. The M156 delivers enough torque down low to mask the sheer weight of the R230, which is complimented by an incredible top-end pull.

The M113K is also a great engine, with less things to worry about/address as preventive maintenance.

All of the examples you listed have their merits. V12 engines do indeed have a "special" feel to them...looking forward to another one down the road.

 

M156 was disappointing, problematic, and short lived. Skip it for the bi-turbo 12 or a R231 SL63. The R230 looks better but the 231 is superior in every other sense.

 

Consider an R231 SL550 as well, looks like *** but very smooth and deceptively fast. Tune and downpipe and you can blow the doors off a M156 SL63. They can be had for around 30K these days, which is on the same price level as the cars you're thinking about.

 

A couple inaccurate conclusions there.

1. Easily made bulletproof with a few upgrades, unlike some of its successors. The bottom end is also very strong from the factory.

2. Short lived? Total production run for the M156/M159 was longer than both the M113K and M157. A variant is still used today in the AMG GT3.

The early R231s look nice but they started screwing things up in the facelift, IMO.

In any case, those TT V8s are serious powerhouses. That tune and downpipe combo for the SL550 is $8K in parts though, which is in striking range to a supercharger kit for an M156.

 

OE can tune the SL550 for $1000 or less, i've seen downpipes for under $1200. $8000 seems like a lot unless upgraded turbos are in the equation.

 

Certainly less than EC and RT. Where are you seeing downpipes for under $1,200? Keep in mind, most M278 DPs out there are for the E550 and not listed as compatible for the SL.

A few options for the SL550 are already discontinued. What I found and was referring to: https://aerosunzusa.com/products/fi-...29948640362593

In all fairness, I wouldn't touch the exhaust on an R231 SL550. A tune is all you need to out-accelerate most cars on the road.

 

Well wrtten review! amazing

I've owned the 2005 SL55 and currently have (will keep) an 09 SL63 with P030.

SL55 is def more of a GT car despite having crazy torque and SC whine, but gearbox is just slow.

SL63, P030 is a MUST. Bigger front brakes 390mm, factory LSD and stiffer tuned suspension. With those combo, theres no comparison to SL55.

 

I think the R231 facelifted SL63 (17-19) looks better than the 13-16 SL63

 

Guys, thank you very much for all the comments and keep them coming.

I am selling some of my 70’s muscle cars and this will be a replacement for them so what I purchase will be a weekend warrior… I think I want to stay under $50k, unless something really calls to me.

I know all the M156 engines built before mid-2011 DO have the problematic head bolts unless they’ve been changed out. I would look for one that has already had the update done.

I do not want to purchase a bunch of modifications but I would purchase a car that has already had them installed (frugal). About the only thing I will change is the ECU tune.

I know the SL63 AMG has the AMG SPEEDSHIFT MCT 7-speed sports transmission but I was thinking that the 2011 or 2012 had a trans upgrade??

I know it will be hard to beat the power of a tuned SL65 @ 604 W/T 670HP, 66 HP increase. It seems that the tune for the SL63 is only 518 W/T 545HP, 27 HP increase.

Anyway below are a few interesting stats that I found on the web, not sure of the accuracy but seems the two are very close.



SL65 Weight 4517

1/8 mile 8.3 s @ 102 mph

1/4 mile 12.3 s @ 123 mph

0 - 60 mph 3.7 s

0 - 100 mph 9.6 s



SL63 Weight 4068

1/8 mile 8.2 s @ 103.8 mph

1/4 mile 12.3 s @ 118.1 mph

0 - 60 mph 4.0 s

0 - 100 mph 9.1 s

 

Sure, the M156's issues can be fixed with new valve guides, head bolts, lifters, and possibly replacement of worn camshafts. Other than that, it's a good engine with the head bolt issues fixed by late 2010 or so we were told. The M159 is a different engine designation with much needed improvements but, again, different based on a previous one where the design flaws were fixed. The M156 was only produced between 2007 - 2011 while the M113 & M113K was used from 1998 - 2011 so not sure how the M156 was used for longer than the M113/k? M275 was used from 2003 - 2014 and is rock solid with no real issues and will handle a boat load of power.

Based on how long or short, depending how you look at it, MB used the M156. I think you can see there are better engines in MB's.

 

1. Superseded OE head bolts and buckets on a healthy engine and you are set for the long haul. Most of the differences (barring the dry sump lubrication) are/can be reasonably added to the M156. It isn't a different architecture we are talking about here but mainly some top-end engine improvements.

2. Talking about the M113K, not the M113. The M156 came into the picture in 2007 and its successor is still in use today. Your claim of that platform being short lived is inaccurate.

3. Never mentioned the M275 but since you bring it up, let's not ignore the cylinder wall scoring issues and coil pack failures, notable for their ridiculous replacement cost.

Most high-test engines from MB/AMG are great. Just about all of them also have their drawbacks and defects that MB/AMG should be held accountable for.

Personally, I'd rather deal with the M156 long term over many engines in MB's recent history. The only AMG engine I trust more in terms of reliability is the M113K, which earned it. Judging by your username, I think you can appreciate that.

 

Thank you again for all the info. Seems a difficult choice ahead. I guess it will come down to problems corrected.

Is there a reasonable power adder that could be added to the SL63? Something more than the ECM 27HP? I do not want to pay $30k to $40k for a car and ad $8k to 10K for power adders..

 

The M113K was used from 2003 to 2011. In fact, the M156 couldn't properly motivate the G class AMG due to the lack of low end torque so they kept the M113k in the G class until the new M157 bi-turbo engine replaced it in 2012. The M156 was doomed when released and was a total dissappointment to most MB drivers who become accustomed to the low end power house of the M113k and the M275.

MB and all other uses of Silitec/Alusil engines can suffer from scoring issues. It dates back to the 70's and I've suffered from it in 70's era Porsche's so nothing new there. MB pretty much used the Silitec/Alusil piston bore in almost all their engines so the M156 is not immune to it either. With that said, I did not suffer from it in any if my MB's and I have owned two M275's past 100k miles each nd my E55 has over 250k miles and is still a beast with nothing ever spent on the engine. There was a bad batch of coilpacks on the M275's initially but the replacement version has not had issues. Both cars had them replaced and neither one had any issues. It's way cheaper than a blown engine from bad headbolts, much faster fix, and won't leave you stranded. Now, the ABC is a totally different story for a different conversation. IMHO, that system is a PITA.

 

In terms of manufacturing duration, fair play about the G and my error. That said, the M156, an engine designed for a racing application, was never intended for the G so not sure why you are trying to spin this as a negative.

Regarding the scoring, that's masking documented failures on a specific platform with a blanket statement. There is no comparable track record of this issue with M156s or M113Ks, which trumps any theory on what is/isn't immune. As for classic Porsche engines, perhaps we should keep this dialog relevant to the platforms in question?

Total disappointment to most? I'm not here to convince you otherwise, but let's not masquerade an opinion as fact. You speak for yourself, not for the majority. Take an actual look at the enthusiast community and how the platform is regarded. Check out the W204 forum for multiple examples of how this engine stands up to track duty, even when modified to its N/A limits.

I'm glad to hear about your experiences with the M275 being positive ones. It's a great engine and something I'm interested to add to the stable in the near future. The point of highlighting the issues is that just about every MB engine has its costly weaknesses which, in most cases, can be sorted out.

Back to the M156, the reality is that:

• The head bolt failure rates are in the single digits, with multiple examples on here of early M156s with up to 150K miles on the originals. The danger is that it's a crapshoot with no early indication of failure, which is why many replace them as PM.
• Updated bolts and lifters can be purchased for a couple hundred bucks and any savvy DIYer can knock out the job in a weekend moving slowly.
• Healthy cams, with very reasonable preventive maintenance, can see 150K+ miles with ease.

As for the ABC suspension, agreed. It's the only part of these vehicles that concerns me for the long run.

 

Now, take the M156, update all the weaknesses, add twin snails or Weistec blower, and you will have a beast. As for the failure rate of the M156, I'm hearing more and more of the bolt failures across the classes as mileage and time increase. Not sure I would say single digits since it seems to be coming more prevalent and from decades of MB ownership I've realized that MB is extremely consistent. When one breaks, they usually all suffer from the same issues. MB was sued early on due to the M156 engine issues so it's not like they were not aware and had already started the process to phase it out and quickly. There is no way that I would own an M156 without updating all the weaknesses and if you are not a DIY'r it will be very expensive.

 

I hear about the M156 head bolt issues across all forums too, so the problem is definitely out there. However small it might be, it would still be on the back of my mind every time i hop in the car, this was the reason i opted for a 2009 SL600 instead of a 63. Another car i was cross shopping with was an M4, however i hear they have crankhub separation failure too, again, although small percentage of people had the issue, it's enough for me to skip it. As far as ABC goes, after 2007 MB updated a lot of the parts to be more reliable, and they made the main high pressure hose very accessible. That's the one that like to burst in the earlier models and that requires basically pulling out the entire under carriage to replace. The updated routing diagram is a straight shot, doesn't snake under the bellhousing tunnel anymore.

 

Why do people feel the need to shove their OPINIONS (not facts) down people’s throats? Every option mentioned here has pros and cons, and each individual should make the best decision for themselves. I love the M156 and greatly prefer it over the M113K and later TT models, you can’t beat the responsiveness and sound of a naturally aspirated V8. I currently own two M156 equipped cars and wouldn’t change a thing. The other options are great too, just not my particular taste, but I totally get why some prefer them. There’s no better or worse, just flavors.

To the OP, you will rarely get much out of a tune on a naturally aspirated engine. AMG didn’t leave much on the table. If you want to make big power with a tune you’ll be much better off with one of the forced induction models.

 

 

I voted for the '05-'06 car, since I don't care for the minor cosmetic changes which came with the MY2007 face lift. Also, I don't see a reason to exclude those two years, and since sales figures for them are much higher, it would be much easier to find the color combination I want.

 

I believe in 2007 they started changing the ABC line to be much easier to replace than the previous ones. I think i read that, but for sure my 2009, they moved that awful main line that goes from the pump to the valve block. My 2005, that line snakes under the trans tunnel, is impossible to do without removing a ton of stuff and it's over 10 hour job. That one likes to burst as it's subjected to a lot of heat, in the updated model, that line is 1/3 the length and is a straight shot from the pump without snaking around. Replacing that would be a hell of a lot easier. That would help out a great deal when it comes time to service the ABC system.

 

The M156 might be a crappy engine but it sure sounds good.

 

I'm not sure what BlownV8's angle is, he seems to be copy/pasting the exact same information and crappy Youtube video onto a number of different threads. Maybe it's his video and he's trying to drive views?

Again, there are pros/cons to every option. If you like the M156 but don't want the fear of head bolts or tappet wear, just buy one that's either been fixed or a 2011+.

 

No angle, the person was asking about what vehicle to get. Not my video and have no personal gain from posting a link. The M156 engine problems are well known and someone who buys a vehicle equipped with the engine needs to be aware of the issues. I would and do say the same for any MB engine that is problematic. The other engine that is extremely expensive to maintain and unreliable is the OM642.