eddieo45

well, my original question boiled down to this: 2 years newer or 2 more cylinders, and I appreciate all the opinions. some on this forum might be deciding between brand new SL550's and SL450's, but that's a completely different conversation.

Since posting this thread I've had the occasion to drive a 2015 SL400 and it was absolutely awesome. It was trimmed out the same as the 2013 SL550 I had driven (black with black/red interior) which made for a great head to head comparison. While it felt lighter and nimbler, the most intriguing difference was the active multicontour seats, which the 2013 SL550 had, but I did not feel working; could they have been shut off in vehicle settings? I also don't recall feeling blind spot or lane keeping assist, which are also included in the driver assistance package that, while optional on a 550 in 2013, was present on the vehicle I drove.

I missed out on a CPO 2015 SL400 that sold for $39,500 while I was in the process of selling my CLK550 and freeing up the garage space. That sale price is affecting my shopping, as the SL400 I drove last week is priced at $44,000 (was $46,000 back in mid-November, and was $44,300 the day before I drove it; that the dealer would make a measly $300 reduction was a bad sign - the CPO one I missed out on had recently had a $1500 reduction). Admittedly the CPO one did not list driver assistance package that is a must-have for me, but at $4500?? And to put that $44,000 in even more perspective, now I'm seeing a 2015 SL550 for $45,000!! Sure it has 58,000 miles (vs. 30,000 for the SL400), but it also has ABC and a Bang and Olufsen sound system. And while both have black/red interior, in the 550 it's Designo.

So, this is a different question that the one I originally posed, but for basically the same $44000/$45000 price, the 30,000 mile SL400 (under warranty till 9/30/2019) or the 58,000 mile SL550, which must've been $20,000 or more higher at original sticker price?

rorywquin

I think you need to decide for yourself. Lower milage, smaller engine some warranty. Higher mileage, bigger engine, no warranty - I think it comes down to which car puts a bigger smile on your face!

bob55

The SL550's power and that lovely 'growl' made it the clear choice for me!...I am sure the Turbo V6 is a fine choice too, but the Twin Turbo V8 for me, really defines what the SL experience is really about.

Note that the 550's engine is 'perfectly positioned' in the middle, between the V6 and the more powerful AMG SL63's V8 engine.

No matter how good any V6 may be, the SL Class is still a car that demands and deserves the power, (and the great sound), of a genuine Mercedes-Benz V8 engine!

So for as long as MB makes such an engine available, that for me will be the better way to go!

rorywquin

We all love V8s however, I can barely stay legal in the V6 let alone with a V8.

There is a price premium for the V8 (and depreciation seems worse) which buys more power that cannot really be used, a muted V8 sound, more weight on front wheels (& tyre wear), worse gas mileage, marginally better 0-60 and less nimbleness (due to added weight over front wheels) .

So in theory V8 bragging rights and not much else.

I thought long and hard about which one to select and ended up with the V6 because all the motoring journalists, that had driven both, preferred the nimbleness, handling and overall drive / feel of the V6.

Streamliner

rorywquin

In the UK - when I bought mine, you could have any option on both cars - so for me the only decision was engine size and ergo, handling. I can afford a V8 but settled on the V6 for all the stated reasons and loaded it with all the options I wanted as well.

Now looking at the E53 AMG - my son has just collected his (coupe) and it is awesome - I'm waiting for the cabriolet. Electric assisted turbo (read zero lag), hybrid boost etc and and a straight 6, 3.0L that will leave many V8s in their dust.

Wolfman

Love the i6 tech; very linear power delivery. It won't beat the SL550 though

Wolfman

It has always been a mystery to me of how seemingly alike engines can command such different markups. If I recall, on the E-Class (W212), the 550 upgrade was only $5-6k. On the other hand, when our first SL550 hydro-locked, the engine replacement with labor was quoted as $70k

threeMBs

How did that happen?

TennesseeZ4

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!

Streamliner

rorywquin

I think there is .1 sec difference - not bad for a much smaller engine and of course older V8s are slower. It also sounds very nice.

Wolfman

On paper it is but in reality in the V8's are underrated. I have heard that the i6 power/speed is somewhat closer to listed specs, but we should know more about real-world performance as more customer will put their cars to the test.

Our old 2013 SL550 clocked in at 4.1sec. (via Vbox) with 4.5sec. listed. Our 2017 is listed with 4.3sec but does 4.0sec (via Draggy) and 3.9sec but that wasn't a clean run. On a good day (temp & fuel), 3.9sec will be very realistic.
But in reality, none of this matters. It's nice if a car is fast but I enjoy how it does it. Our old-school V12TTSL was clearly slower than either the i6 or the V8 but the locomotive-level torque delivered a grin-inducing experience that can't be quite matched

That said, I am a strong proponent of the i6. It's the most modern engine design on the market today.

Wolfman

Flash flood. We were driving and there was a dip in the road with maybe 8" of water height. The car pushed a wake in front and some water made it into the intake. Took all but a couple of seconds and not a drip of water in the car. I truly thought this was an electrical short.
Needless to say I was surprised when I heard the next morning that the engine was destroyed...

rorywquin

Happened to a friend of mine in an Audi.

places

100%. It's there, and it's there always and instantaneously. The range is deep and constant without the engine working that hard. It's effortless.