My take: ///M-DCT vs PDK vs GTR DCT vs AMG Speedshift 7 Speed MCT

[-=Hot|Ice=-]

Over the past couple of weeks, I've had the opportunity to drive a few cars and really explore what these transmissions can do. The last time I tested the M-DCT was back in 09 when it's shifts were clunky and it would fall on it's face at low speeds. All the transmissions listed here are all amazing and do their intended purpose without flaw(drive in stop and go traffic and cruise on the highway). Lets get into it.


AMG Speed Shift 7 speed -

HUGE improvement over the old 7 speed. Much less jolting. Faster, smoother shifts,but it still 'lags' from time to time. From my understanding it replaces the torque converter with a wet clutch pack, like a motorcycle. While that's all hunky dory and cool, this transmission still 'thinks'. It stumbles from time to time. When I hit the shift pedal, it means I want you to shift now...not 2 seconds from now. Still, it's nothing short of an impressive. AMG has worked their magic on this one. It just can't compete with the DCT's in the segment that provide crisper, more responsive shifts. The transmission has the ability to double de-clutch on downshifts but that's where I found the transmission to have most of it's problems...downshifts. You press the padel and you wait a second and then...BAM it slams into gear. This only happened 3-4 times but compared to the others, it stood no chance. Placed 4th(last) in the group


GTR's DCT -

The GT-R's DCT is simply, one of the best available. It's shifts are lightning quick yet very smooth. It was a bit clunky at lower speeds but maybe because the car hadn't had a chance to warm up. Anyway, it doesn't seem to be as refined as the others. You hear everything that's going on. There's as slight whine coming from the box. Nicely executed though. The blistering fast shifts is one reason I think the GT-R is so quick. This ranked 3rd in the group.

PDK -

Quick and smooth is the name of the game here. This transmission is simply amazing. It came in a VERY close second. I loved how I dropped it down say from 5th to 2nd and the car wouldn't even twitch. No bumps, No jerks...quick and smooth. This thing went through the gears so professionally it was uncanny. It could make the stupidest of drivers look like they're a pro. The PDK in this car though, was constantly hunting for 7th. It wanted to get to 7th as soon as possible and stay there. I hated that. One of the major gripes I had. Not sure if this is a trait of ALL PDK's but this really annoyed me.

M-DCT -

The last time I tested this transmission was back in 09 when it simply put, was awful. Jerky, twitchy, annoying. Low speed changes were a hassle. It was smoother then the SMG and a bit less clunky but it still had SMG traits. That has now been fixed. This transmission in my opinion matches if not beats the PDK AND GTR DCT. Instantaneous shifts, crazy quick reaction. The car would never lose it's composure under any condition. I put it through it's paces a few times dropping it down from 7th to 4th or from 4th to 2nd or 1st and it took it in stride. Begging you to give it more or try it again. BMW did it right. The car never hunted for gears and stayed in the proper gear each and every time. Changes were crisp and clean. No extra drama. Car would shift whenever I told it to. I Loved it! I liked how you could make the shifts crazy fast or ridiculously slow. This is my winner. 1st place.


BMW has come a long way with their ///M-DCT. The PDK for the longest time I thought was top dog but that certainly isn't the case anymore. The GT-R's transmission while I think is the standard, doesn't offer the civil nature that the M3 and PDK offer. I don't need to hear whining from the box while I'm cruising. Like I said, all of these transmissions are amazing in their own respect BUT honestly, I don't know how the M Division has pulled it off but they did.


Sorry for the long review. Just wanted to share my thoughts.

[nv6425]

Great review...I drove a PDK this past Saturday and agree that it's a very close 2nd to DCT, but still 2nd!

[-=Hot|Ice=-]

Originally Posted by nv6425

Great review...I drove a PDK this past Saturday and agree that it's a very close 2nd to DCT, but still 2nd!

Thanks! All very good but there can only be one winner!

[klammer]

DCT is fantastic in this car. Try it at the track. WOW!

[gblansten]

Thanks for the review. Appreciate the feedback.

[RudyP]

Thanks for the review - it agrees with what I have heard. I wonder how Ferrari's version (in the 458) would stack up.

In the 6MT world, I can tell you that the order is reversed. I have a 2011 E92 M3 and a 997 Carrera S both manuals and the Porsche has the BMW beat in shifter feel, precision and shorter throws. They're both good but the M3 is a little rubbery and vague compared to the Porsche's mechanical, crisp and precise feel. Both are a little notchy though.

[hgtran21]

nothing beats the s2000 shifter imo

[-=Hot|Ice=-]

Thanks for the kind words, everyone.

[JustMpwrd]

I've always wondered how these different trannys stack up against each other. Thanks!

[WCH]

I had a chance to drive a 458 Italia. The whole car is a different experience and I was on a track, which is different than how mostly drive my M-DCT M3 (not much opportunity to drive full out in 2 and 3 gear). The Ferrari is simply a different beast so it is hard to compare. My brief sense is that it is less smooth than M-DCT but that is in character with the 458.

Drive a GTR, an R8 and a Gallardo at the same time. Agree with the assessment of the GTR. The R8 and Gallardo were similar to M-DCT though I would need to drive them on the street to really know.

All of them are awesome cars (including the M3).

[clar]

Originally Posted by WCH

I had a chance to drive a 458 Italia. The whole car is a different experience and I was on a track, which is different than how mostly drive my M-DCT M3 (not much opportunity to drive full out in 2 and 3 gear). The Ferrari is simply a different beast so it is hard to compare. My brief sense is that it is less smooth than M-DCT but that is in character with the 458.

Drive a GTR, an R8 and a Gallardo at the same time. Agree with the assessment of the GTR. The R8 and Gallardo were similar to M-DCT though I would need to drive them on the street to really know.

All of them are awesome cars (including the M3).

Both the R8 and Gallardo uses sequential manual instead of dual clutch.

[WCH]

Originally Posted by clar

Both the R8 and Gallardo uses sequential manual instead of dual clutch.

Yes. True - hard to tell what it would be like on the street as driving on the track changes some of the priorities while driving.

[W Cole]

You say the DCT has come a long way since 2009. Unfortunately, I have a 2009. Can I get a software flash that will make it as good as a 2011 or is there a mechanical difference?

[-=Hot|Ice=-]

Originally Posted by W Cole

You say the DCT has come a long way since 2009. Unfortunately, I have a 2009. Can I get a software flash that will make it as good as a 2011 or is there a mechanical difference?

The software update will fix it! Your car should of gotten it by now! If not, go to your dealer and get it done!

[lve2xlr8]

Awesome comparison and thread, I've spent significant time with the PDK (Boss's Cayman R w/Sport Chrono) and DCT (My m3), but I'll add my thoughts:

The PDK to me behaves a little more traditionally, people who don't know how to drive stick or paddle shift gears will appreciate how the car will lurch by itself when you leave the brake and how the shifter is identical to a typical automatic. The shift speeds--although incredibly fast--will never jerk into the next gear and will very rarely chirp the tires into 2nd. The downshift rev-matches don't scream like those of the DCT either, again they're still very (just as?) fast. Thankfully the Cayman R has real paddles similar to (but nearly as nice as) the DCT. The poke/pull levers in other Porsche PDK models are a joke. I also don't like how pushing forward on the console shifter upshifts, DCT's pull to upshift feels more natural.

Things I like about the PDK are that it seems to launch the car at exactly how much throttle you're feeding, whereas the m3 it's either regular start or dump the clutch at high rpm start. I also like the pop noise the pdk makes when it upshifts at light throttle. PDK is less reluctant to downshift to first than the DCT. Another thing is when you floor the DCT--say from 7th to 3rd--it seems to sit for a second before it takes off, not a big deal, but the PDK seems to do this a little more seamlessly. And finally, I feel as though the PDK goes from D to R and vica versa much faster than the DCT.

I prefer DCT for several key reasons (reasons that also won me over from the 6mt.) The aforementioned trumpeting downshifts are like crack, I can't get enough of them, the upshift slamming of gears on the faster shift settings also feels incredible. I like how if you come to a complete stop and release the brake the car sits until you touch the throttle. I like the funkier shifter setup, I think it's contemporary and cool (although I'm constantly turning other cars off without putting them into park). I definitely prefer the large gear indicator over the tiny one off to the right in the Porsche.

Both awesome transmissions, but the PDK loses when it comes to the sublime shifter in 6mt Porsches. The DCT wins when it comes to the rubbery (and tough into 2nd) feel of its counterpart 6mt.

The PDK is seamless, and does it's job with no drama. That's why I prefer the DCT.

[-=Hot|Ice=-]

Originally Posted by lve2xlr8

Awesome comparison and thread, I've spent significant time with the PDK (Boss's Cayman R w/Sport Chrono) and DCT (My m3), but I'll add my thoughts:

The PDK to me behaves a little more traditionally, people who don't know how to drive stick or paddle shift gears will appreciate how the car will lurch by itself when you leave the brake and how the shifter is identical to a typical automatic. The shift speeds--although incredibly fast--will never jerk into the next gear and will very rarely chirp the tires into 2nd. The downshift rev-matches don't scream like those of the DCT either, again they're still very (just as?) fast. Thankfully the Cayman R has real paddles similar to (but nearly as nice as) the DCT. The poke/pull levers in other Porsche PDK models are a joke. I also don't like how pushing forward on the console shifter upshifts, DCT's pull to upshift feels more natural.

Things I like about the PDK are that it seems to launch the car at exactly how much throttle you're feeding, whereas the m3 it's either regular start or dump the clutch at high rpm start. I also like the pop noise the pdk makes when it upshifts at light throttle. PDK is less reluctant to downshift to first than the DCT. Another thing is when you floor the DCT--say from 7th to 3rd--it seems to sit for a second before it takes off, not a big deal, but the PDK seems to do this a little more seamlessly. And finally, I feel as though the PDK goes from D to R and vica versa much faster than the DCT.

I prefer DCT for several key reasons (reasons that also won me over from the 6mt.) The aforementioned trumpeting downshifts are like crack, I can't get enough of them, the upshift slamming of gears on the faster shift settings also feels incredible. I like how if you come to a complete stop and release the brake the car sits until you touch the throttle. I like the funkier shifter setup, I think it's contemporary and cool (although I'm constantly turning other cars off without putting them into park). I definitely prefer the large gear indicator over the tiny one off to the right in the Porsche.

Both awesome transmissions, but the PDK loses when it comes to the sublime shifter in 6mt Porsches. The DCT wins when it comes to the rubbery (and tough into 2nd) feel of its counterpart 6mt.

The PDK is seamless, and does it's job with no drama. That's why I prefer the DCT.

Great write up! Thanks for sharing and adding!

[creepy coupe]

Interesting write-up, but I'm curious as to how well you tested the above gearboxes, You stated the GTR's DCT was a bit clunky, maybe because it wasn't warmed up. I'd have thought you would need a good long run in each car to fully appriciate their differences?

[mkoesel]

Nice write up Hot-Ice.

Mercedes should can the planetary MCT box and just put the DCT from the SLS in all the AMG cars.

[-=Hot|Ice=-]

Originally Posted by creepy coupe

Interesting write-up, but I'm curious as to how well you tested the above gearboxes, You stated the GTR's DCT was a bit clunky, maybe because it wasn't warmed up. I'd have thought you would need a good long run in each car to fully appriciate their differences?

Re-read what I wrote for the GT-R. I already admitted that the car hadn't warmed up. I also admitted that that the gearboxes are all phenomenal in their own right BUT in my opinion, the M-DCT I think is the one that I feel was the all around best one.

[-=Hot|Ice=-]

Originally Posted by mkoesel

Nice write up Hot-Ice.

Mercedes should can the planetary MCT box and just put the DCT from the SLS in all the AMG cars.

Thanks! Yes they should. It would make a world of a difference.

[e90m3_6MT]

I test drove a 2011 DCT and you're right, my god it's good,

I found myself constantly shifting just to hear those beautiful rev match downshifts, I mean I can do them easily with my manual box, but the sound isn't exactly the same, it somehow sounds more special with the m-DCT.

[creepy coupe]

Originally Posted by -=Hot|Ice=-

Re-read what I wrote for the GT-R. I already admitted that the car hadn't warmed up. I also admitted that that the gearboxes are all phenomenal in their own right BUT in my opinion, the M-DCT I think is the one that I feel was the all around best one.

What else did you write about the GTR other than this?

GTR's DCT -

The GT-R's DCT is simply, one of the best available. It's shifts are lightning quick yet very smooth. It was a bit clunky at lower speeds but maybe because the car hadn't had a chance to warm up. Anyway, it doesn't seem to be as refined as the others. You hear everything that's going on. There's as slight whine coming from the box. Nicely executed though. The blistering fast shifts is one reason I think the GT-R is so quick. This ranked 3rd in the group.