SL450 vs. SL550: I knew it wasn’t just me..............
 

I bought my V6 powered SL450, instead of the 550, because I much prefer the way it drives. Much lighter on its feet, smoother, more nimble and sporty. I feel the 362hp and 369 lb.ft. of torque are way more than I will ever need in a luxury cruiser. Funny, but today I received a review on the upcoming GLS SUV, and here is what Automobile Magazine said about the six vs. eight cylinder models:

You might think that the GLS580’s potent V-8 would be the no-brainer, with its stonking 483 horsepower and 516 lb-ft of torque, but we actually preferred the GLS450’s inline-six despite it making “just” 362 horsepower and 369 lb-ft. Why? Because the six-cylinder’s interaction with the 9G-Tronic nine-speed automatic transmission was far smoother, more refined, and more consistent across all types of driving.

While the 580’s power is certainly impressive, the 450 is never left feeling slow or balky despite the GLS’s likely 5,500-ish-pound curb weight (Mercedes has yet to release final weights for the vehicle). That fact is reflected in the marque’s claimed zero-to-60-mph times: The 580 is quoted at 5.2 seconds, while the 450 is very close behind at 5.9. Will you ever miss that three-quarters of a second in the real world? Not likely. But you will appreciate the regal smoothness of the GLS450’s engine/transmission combo every time you drive.

I know I do, every time I drive. I guess great minds think alike. :D

When I bought my second SL I felt the same way and opted for the SL450 though I could afford either one.
The 9 speed transmission is awesome.....

I do prefer the V8 because I do crave power, and I hope to find something even more powerful to replace it in the future. I dislike the V6's sound and fake exhaust generator, but I did appreciate the handling. However, I don't live near any twisty roads so power trumps handling in my case.

Couple clarifications here...

The engine in the new GLS is the new i6 not the one older V6 in the SL450.
The reason why the SL450 is such unique value statement is that the car can be optioned the same way as the SL550, leaving a large price difference to the engine alone. This is not the case with other models, such as the GLS which has unique trims for the V8 that can't be had on the 450.\

The SL450 has a sound generator and so does the SL550. Both cars have exhaust flaps now. From what I understand it is only used for startup but that is easily tested. I prefer the SL550 sound as it has a more subtle exhaust note than the SL450. Btw. early R231 SL550's sound nothing like the later models and have no flaps.

In the end, people pick what they prefer to drive. There is no better option, just the personal preference. If it comes at an additional cost or at a savings, that's cool either way :)

Yes, know about the I6 vs. my V6, but found it very interesting that the stated HP & torque ratings are both exactly the same.

Ditto - I read every road test I could find on the facelift and ended up convinced that the V6 was the better option. I live in a village surrounded by twisty roads and great drives to the nimble (lighter front end) made more sense for me.

However, I'd be happy cruising the PCH in a V8.

Interesting that you say that, as PCH (Pacific Coast Highway) is pretty much the ONLY road I drive my SL on.

Yep beautiful drive.......- we drove from San Diego to Vancouver (BC) and back to Seattle a couple of years ago in a RV and I regretted not getting a nice highway cruiser and staying in m/hotels instead. however, we thoroughly enjoyed the trip.

Coming from a C7 Corvette with 460 HP I was a bit concerned that the V6 would seem anemic but driving one convinced me that it was plenty adequate for the kind of driving the Mrs. and I will be doing in the SL. It cruises at 75 mph at around 2K RPM and around town has plenty of pep. I didn't drive a V8 so I can't compare it but I'm satisfied with the V6. My main concern is reliability and hope that it proves to be very reliable.

On the subject of of the 450...my wife and I did the European Delivery in May, the car is in Baltimore Port and I can't wait for delivery. QuickJack is raising their prices July 1 and I'm trying to decide between a BL-3500SLX or a BL-5000SLX lift. I don't know what the lift point spread is on the 450; I also have a '16 GLC & if my calculations are correct, the points are 57/66 which is too long for the BL-3500SLX. Advice?

It’s not an “exhaust generator”, it’s a variable passive acoustic resonance device. Lots of cars use them on the intake side to quell nasty intake honk, and as Wolfman pointed out, nobody complains about “exhaust flaps”, which accomplish pretty much the same thing (by varying the internal volume of the silencers). The difference is, while flaps mostly tend to vary the loudness, the “generator” mainly varies the note/tone. The “generator(s?)” on the 450 are probably there to smooth out the exhaust note when the flaps are open. I’ve heard these cars winding out and they sound very sweet and refined...very much unlike, say, a Jaguar V6, which just sounds loud/ratty/raspy IMO.



We did that drive a couple of years ago in a rented Mustang convertible, staying in m/hotels. That road is like another world...in places there was a 20m-thick blanket of fog on the ocean that just stopped right at the shoreline like there was a glass wall at the water’s edge. I’ve never seen anything like it. Fantastic drive...

I’ve been wondering if we’ll be seeing this new inline six in the 231 before its replacement arrives in a couple of years...

Do you have ABC?

I believe that there is no way MB will spend one more Euro on the R231, for much of anything, let alone the huge expense involved in fitting the I6 to the car. No, the sweet spot for the R231 is right now and to anyone who might be on the fence about ordering a new one, I highly recommend placing your order ASAP. Of course, there is an outside possibility that there could be a MY21 R231, but probably not. 2020 is probably it for this wonderful car and the clock is ticking.

I took my daughter’s GL450 to the car wash yesterday. It is amazing to me that this huge, very heavy truck does not feel under powered, with the same V6 as in my SL, and her’s is a 2014 with the old 7-speed.

l think what the deal is, for so many of us older guys, is the idea that we were brought up in an era when having a “six” under the hood was tantamount to driving an “old lady’s” car and having a V8 was the only way to go for a guy looking to lay a little rubber. These modern power plants are so advanced and sophisticated, producing so much incredibly smooth torque and horsepower, and when mated to a transmission like the truly amazing 9G-Tronic, the result is performance that puts many exotic cars of not so long ago to shame. But, to many old guys, myself included, the idea of two fewer cylinders still conjures up the idea of a 1954 Chevy “stove bolt” six. Of course, I tend to forget the fabulous inline sixes in the Toyota Supras I owned in the 80’s or the stunning performance of my long gone 911’s. As we enter what is most likely the twilight of the internal combustion engine, I am thrilled that I got to experience this little car. It puts a smile on my face each time I drive it.

Wasn’t the 2014 version of the V6 “only” rated at 329 hp? So, even more amazing.

I briefly had a late model Charger rental with a V6 and an 8-speed automatic and was really surprised at how well it ran.

I posted this a bit ago (year or two?), but still applicable to the conversation: Following the Sl550 vs the SL400/450 conversations for the past few months, I did my own road test this weekend, with a friend who has an SL450, swapping off for a comparison. To me it comes down to really one difference, and that is torque. The 550 will plant your rear end in the seat at 60 mph and keep it there to well beyond 100. The 450 delivers decent performance in that range, but not on the scale of the 550. On normally twisty roads, at speeds that did exceed the noted limit, there is a bit more push from the front end of the 550, but not demonstrable understeer. But it is that low end and mid-range torque that really differentiates the two vehicles. Factor in fuel economy and the fact that most of don't really drive the cars that hard, and it's hard not to make a case for the V6. But sit behind a line of five cars doing 75 ~ 80 mph in the left lane on the interstate, and then have an opening on the right lane, well that is where the extra uumph of the V8 really shows. While I did enjoy the SL450, and found it to be a quite capable SL, I am still firmly in the SL550 camp. It's the torque that does it for me, and it is immediate at highway speeds which I do enjoy. Either one will be a most enjoyable vehicle to tour in, so you just have to make your choice and embrace the ride!

I have owned three in line six cylinder BMW's, 3.0 and 3.5 liters. Perhaps the finest engines ever built, smooth torque, effortless acceleration, and a most enjoyable sound. The new 3.0 in line six from MB, with the lack of ancillary drives via the 48 volt system, and electric supercharger, is most intriguing. That to me would be a great engine for the SL, perhaps we will see it in the next gen cars. But I am not ready to leave the most impressive torque of the 4.7 V8, for the moment. And my first car was the 235 Blue Flame six cylinder Chevy 'stove bolt' six in a 1954 Chevy Belair. That car was rock solid, inexpensive to maintain, and got great fuel mileage. Of course it could have been enhanced by use of the three speed on the tree.

Well said

Sales of SL models are decreasing. Has it been confirmed that there will be a successor to the R231?

There will be another SL but expected to be significantly different from today’s - you can search this forum for a lot of info and speculation. Generally expected to have soft top and 2+2 seating - maybe a more luxury oriented AMG-GT? It may have some features superior to the r231 (chance to correct audio deficiencies for one), but lack of a folding hardtop giving true coupe/convertible in one form means I will be holding on to my 231 until I’m too old to drive it.

Yes the rumor so far is that they are discontinuing the S Class Coupe so the new "SL" will combine the luxury of the S, the "Sportiness" of the SL, a cloth roof (That I am not totally against is cheaper and lighter and can be made to look VERY nice (BMW 6/ Porshce 911 come to mind). Even Mighty Mercedes has to bow to the consumer who simply do not buy many coupes and convertibles anymore.

Glad I bought mine when I did. A folding hardtop is the main feature we wanted.

Same here. My CPO '17 SL63 is absolutely amazing - easily the finest automobile I have ever, and may ever own.

So far, my best SL has always been the next one ;)