SL/R231: Sl63 vs sl550
I'm just wanting to know if there were many changes between the 2 besides the engine. I'm also wondering about the reliability of both the SLs as they are gonna be my new daily. Any thoughts would be great, thanks.




I'm also wondering about the reliability of both the SLs as they are gonna be my new daily. Any thoughts would be great, thanks.
Mileage of both cars?
If both cars are similar mileage and same $$$$, then the SL63 is a no brainer from resale value alone. Depending on where you live, using the SL63 to it’s full potential may be a rare occurrence. The SL550 will be a softer ride and more behaved in bumper to bumper traffic. But if you’re driving an SS you’ll probably want the AMG version of the R231

Arguably, it’s almost a different car…
Good Luck
Last edited by crconsulting; Jun 12, 2023 at 07:34 PM.
If both cars are similar mileage and same $$$$, then the SL63 is a no brainer from resale value alone. Depending on where you live, using the SL63 to it’s full potential may be a rare occurrence. The SL550 will be a softer ride and more behaved in bumper to bumper traffic. But if you’re driving an SS you’ll probably want the AMG version of the R231

Different suspension / tune, different transmission and limited slip differential (P30 option in ‘13). Also brakes are larger to handle the extra power.
Arguably, it’s almost a different car…
Good Luck




The biggest complaint for some would be the transmission (multi clutch vs slushbox). Some harshness, laggy paddle shifts. Nothing major. Just don't use the paddles and go Sport+ and you are good
The AMG would be the better deal but it's worth driving both. Post pics/specs for more details
Trending Topics
The Best of Mercedes & AMG
I was like you when I first started looking, and decided to go with a '17 SL450 due to reading that certain things were improved starting in '17
I was really worried about the top hydraulics, as they are expensive to repair when they stop working correctly and the '17's were supposedly improved over previous years.
And I am not sorry that I coughed up the extra money and went with a 17 over a 13.
And the Bi-Turbo V6 and 9 speed trans is AMAZING!!!!!
I love it!!




For reference, we owned 3 SL550's and drove SL400/450 pre/post facelift models for about 4000 miles+ throughout Europe, so apart from my personal preference at least I feel to be able to speak from experience of how these cars perform in most common situations. To be sure, all SL's are great cars and there is no loser or winner, just better fits for personal preferences.
I recently have been thinking about the 400/450 vs 550 discussions we have had in the past on this forum.
The SL450 is a wonderful car whose most significant benefit was based on a much higher price/value proposition when purchased as new. Even better when leased due to MF subsidies. Now that these cars are no longer the current model, the significant price differential of $20k+ when similarly equipped have now shrunk to much smaller amounts in the used car market. Thus one of the main benefits is not as relevant anymore...
Perhaps it's a question of how the car drives. It's often cited that the SL400/450 feels less front heavy, lighter on its feet and more agile. This is true to some extend as this is a front engine car but less significant than quoted. The weight difference is only around130 lbs. and more recognizable when the 550 is equipped with springs.
With ABC that feeling disappears to a large extend; in fact after driving both cars for extended periods I couldn't tell.
The other 2 differences are the performance (0-60 mph and 60-130 mph) and while the V6 is a great engine, (to me) it lacks the torque and more importantly the ease in which the car passes at speed. There is no benefit I could see selecting a v6 over a V8. The second difference is sound and this goes more for the facelift models as both variants were designed with a louder exhaust (including speaker induced startup sound). Here the 450 definitely sounds louder and sportier. I found that to be a bit of a nuisance and clearly prefer the quieter V8. It also backs up the noise with performance.
Everyone has different expectations and for most the 450 is definitely quick enough but now that all cars are used cars I find that the SL550's may be the better deals. Many are well equipped and previously pricey options are now just pennies on the Dollar.
Last edited by Wolfman; Jul 11, 2023 at 07:49 PM.




Streamliners SL is definitely a unicorn. No car like his anywhere in the US and beyond, but he also did what (nearly) nobody would do. Get a new car configured to his liking, then spend another 20-25% of the new car value to add new brakes and wheels. The result? A perfect fit for him and worth every penny. Happy he decided to keep the car!
Last edited by Wolfman; Jul 13, 2023 at 04:17 PM.

When I was a young man, of course I lusted after powerful sports cars, as the alternative was reasonably under powered cars. However, these days, most every pedestrian econocar has plenty of get-up-and-go to spare. So, the manufacturers have taken the “way too much power is not enough” approach and are building obscenely powerful vehicles for street use. Unfortunately, the vast majority of these monster vehicles end up in the hands of those who have no idea how to drive that much horsepower and think it is best used to show off, disturb the peace and to rev up their macho image. In far too many instances, these crazies end up wrapping themselves & innocent bystanders around telephone poles.
My SL450 has 369hp. It is very quick & way faster than I will ever want or need to drive. The ONLY legitimate reason to have such a car with more power, is if the car will be tracked. All other uses, on public roads & highways in the USA are illegal.
In addition to being powerful enough & extremely smooth, the lighter weight V6 model—especially when mated with ABC & reasonably sized wheels—offers ride comfort & handling that I did not know the R231’s were capable of, until I drove one. In my opinion, the SL450 should have been the ONLY R231 variant, at least in the USA.
Of course, this is all my opinion and I know many of you will disagree. That’s what makes the world go round!
Last edited by Streamliner; Jul 13, 2023 at 11:45 AM.
Streamliners SL is definitely a unicorn. No car like his anywhere in the US and beyond, but he also did what (nearly) nobody would do. Get a new car configured to his liking, then spend another 20-25% of the new car value to add new brakes and wheels. The result? A perfect fit and worth every penny. Happy he decided to keep the car!




In terms of spec, the 65's feature the nicest specs which makes sense given its $200k+ price tag. AMG trim, yet very bling with a lot of chrome. Somehow this works through; it's the best looking of the SL's IMO. Same for the interior. The only SL with a full stitched leather headliner and the most luxurious cabin with diamond stitched nappa leather on the AMG seat trim and door panels. A lovely place to be in.
In terms on engine, the engine didn't feel much different than our older SL600TT but has been revised to be much more maintenance friendly and the old 5 speed slush box has been replaced with a 7 speed version. They are better suited for the massive torque as compared to the MCT from the 63. A much better shifting transmission. The car isn't particularly quick and slower than than the 63 but it goes about it like a locomotive. Endless torque that smoothly pushes you back in the seat at any speed. Very different than the harder kicks of the 63. This is the most smile inducing SL as the grand tourer convertible. It is such an enjoyable car to drive.
It does feel front heavy because it is, but ABC hides most of it. Definitely not a canyon carver though

The ABC AMG suspension is firmer than the 450/550 when optioned but a touch smoother than the SL63. Firm enough for Streamliner to hate it

This is a gorgeous car that could be had for cheap as a used car until MB decided to stop making it. In virtually no time, all inventory was bought up and now they are all but impossible to find and if, they are big money.
Last edited by Wolfman; Jul 13, 2023 at 06:35 PM.

This is a gorgeous car that could be had for cheap as a used car until MB decided to stop making it. In virtually no time, all inventory was bought up and now they are all but impossible to find and if, they are big money.




