FishtailnZ

MB/AMG seem to be bending over backwards to say there won't be an R171 SLK63, but with the SLK350 getting upgraded to 300hp for the 2008 midlife upgrade, will AMG leave the SLK55 alone? Well what about this possibility - dumping the SOHC 5.4 for the DOHC 5.4 just recently introduced in several lines?

Right now the SLK is the last model to use the older SOHC 5.4, so why wouldn't MB want to end it completely and use the DOHC version only? Since it is basically a DOHC head on the same block as the SOHC version uses, the fitment issues surrounding the new 6.3 would be eliminated. And with a boost of 20, aproximately, in both hp and torque, it would carry the SLK55 gracefully to the end of the R171 cycle. Hell, they wouldn't even have to change the name - SLK55 since displacement for both SOHC and DOHC is the same.

PC Valkyrie

The 5.5 L DOHC V8 making 382HP in all of the "550" series cars will never make it into any AMG vehicle simply because AMG cars "must" have an AMG tuned or developed engine.

By the way, where did your read that the SLK350 will be upgraded to 300HP for MY2008?

Also, the new 550 series engine is indeed a 5.5L DOHC V8 and is completely different from the AMG tuned 5.4 L SOHC V8 found in our C55's and SLK55's. Our old 5.4L V8 is basically the old 5.0L V8 found in the previous "500" series cars but bored out and modified by AMG.

MercedesFTW

What V6 would they use/how would they tune the 350 for the 300hp output?

FishtailnZ

First on the SLK350 - MB has already revealed the upgraded 3.5L engine with direct fuel injection (CGI) giving 292hp for the 2008 model year, to be used across the board in whatever models use the current 3.5L. I first read about it in a couple of mags earlier this summer, and it's been discussed some in the SLK350 forum(s) on a couple boards.

Re the SLK55, just speculation on my part . How far away is the R172 - 3, 4 years? I don't see MB keeping the status quo on SLK55 (what with the new 400+hp V8 powered versions of the M3/Roadster/Coupe right around the corner) for that long without some changes to keep it fresh. Maybe they'll put the black series spec engine in, I just can't see them doing "nothing" while competition passes them by. Even a 300hp SLK350 will be knocking on the door performance wise of the current SLK55. But again, just speculation on my part.

ronaldtheologo

Oh I thought you were talking about mid-life as in turning 40 in age.

Do you think the $15,000 difference between the SLK 350 and SLK 55 is worth it?

I want to buy an SLK 55 but wife says it is too much for me. I can afford it.

chrislk55

I turned 40 this year and purchased myself a brand new SLK 55. Oh I feel soooooo much better now ! Happy to be in a Mid-Life Crisis

LETO

That is the smallest difference between any mercedes model and it's AMG counterpart and it is well worth it. You can load a SLK350 all the way to the base price of a 55 with options a 55 with everything but 030pkg is 70K

FishtailnZ

Welcome to the club!

Shinigami

The 5.5 liter DOHC is not an AMG engine, but it doesn't mean this engine won't find its way into an SLK...

When the SL55 AMG came out, MB responded by making the SL600. For AMG to stay one step ahead of MB, they then released the SL65 AMG.

I think, if MB decides to make an SLK550, then AMG "must" respond by making a 55 or 63 with much, much more power. They always try to stay a good 100hp ahead of MB (i.e. non AMG Mercs).

However, I think what "might" be happening, is that if the SLK350 ends up having 292hp, then AMG might pump out an SLK55 with something like 400hp. They've already done it with the Black Series, and if they're able to sell the entire allocation of Black Series SLK's (what was it, like 400 or 500 cars?), then that's when they will start to worry about a more performant SLK.

But also, it might mean that they don't want to shoot their existing customers in the foot. For example, the Black Series, although with 400hp, also weighs less, yet costs quite a bit more then a standard 55. So if they make a standard 55 with 400hp, it wouldn't be quite as fast as the BS due to the weight being a few hundred LB's more, and this way they could still keep it costing in the range of the current 55.

If however they go for a 63, the car would be serious competition for an SL55/600/65... and MB probably doesn't want their existing SL customers to be threatened by an MB which costs 2 or 3 times less with the same performance.

Anyway, who knows...