SL/R231: SL450 vs. SL550: I knew it wasn’t just me..............
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.




The 9 speed transmission is awesome.....
Last edited by Utopia Texas; Jun 24, 2019 at 11:56 AM.




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
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

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


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...
Last edited by Dr. Manhattan; Jun 28, 2019 at 10:13 PM.
However, I'd be happy cruising the PCH in a V8.
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.


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.








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.
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.
Last edited by TennesseeZ4; Jun 29, 2019 at 10:23 PM.







