7-speed autoboxes

[izzyloveslizzy]

Well good at least you have enough sense not to take an Alfa to the winderness! Just kidding by the way. I think I'd probably take a 'normal' car to the outback for a round or two of rolling in the mud and snow. It's all good clean (!) fun!

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Hallo fastsaloons.com,

 

kennst du schon 7-speed autoboxes (Anzeige)? Dort ist vieles zu finden.

 

Mercedes Ersatzteile (Anzeige) | Mercedes Tuning (Anzeige) | Mercedes Uhren (Anzeige)

[Mihai]

the 7 speed autobox will debut in 2005 on the s and ml class.

[izzyloveslizzy]

I see. It looks like they're putting it on the heavier models first. But why?

[thepolarfoxqx]

because the gearbox itself is very large and heavy. Furthermore it is expensive.

[izzyloveslizzy]

Yes but ironically I think it would be more fit for the 7-speed to appear in the fast-coupés first. Oh well, I guess one can't ignore costs. In any case, I think BMW has some competition on it's hands, which means they probably won't be standing around for long, looking on. For all we know they have a 7-speed up their sleeves right now.

[thepolarfoxqx]

ZF (zumelfenfabrik fredrickson - yes, i know I botched the spelling) has said that their wide ratio ZF6 speed is plenty. Seven speeds is too many. 7th has to be for cruising at unreasonable speeds, and 1st has to be goofy short (I had an A4 with a 5 auto, 1st gear was goofy short on that). The gearing on 7 series is already geared plently tall. 6th is great, I really can't see a need for 7.

I think the future is in constantly variable trannies - not ones that can cram the most cogs in a box.

[izzyloveslizzy]

Absolutely, but there was never a need for a V12 large-size sedan either. Though as soon as BMW did it, MB came up with one as well. That's the whole point. The two companies are always trying to out-do eachother with technological - iff sometimes pointless - innovations and additions. I don't see a need for a 7-speed either. But if one of them made an 8-speed ( ) the other would do it too. And I think by now it's pretty obvious why!

[thepolarfoxqx]

ZF (they do jaguar and BMW trannies), Ford, GM, and VW have all made it clear they are doing SIX speed autos. I think Merc may be alone on this one. Many japanese firms, plus VW/Audi have shown interest in the constantly variable transmission. That makes more sense.

You all realized how big a 7 speed box is right? To make it worse, it is made by mercedes, so it will weight a ton too (merc makes great trannies, they just tend to be very very heavy)

[izzyloveslizzy]

I honestly don't know how much heavier MB trannies are.

I only mean that if MB is really successful with the 7-speed, then the others are gonna want a piece of the pie. CVT or not!

[thepolarfoxqx]

what is the difference between a six and a seven.

Weight:

Mercedes Benz 5spd auto used in 2002 Jaguar XJ is 115lbs heavier than ZF 6spd auto in 2004.

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Hallo fastsaloons.com,

 

schau doch mal hier zum Thema Mercedes (Anzeige)? Eventuell gibt es dort etwas Passendes.

 

Der V16 Motor zum Selberbauen (Anzeige) ist auch genial.

[izzyloveslizzy]

You know now that you mention weight (a few times!) a 7-speed manual would be lighter than a 7-speed Auto, so maybe MB ought'ta go for that one instead. Wouldn't that be a more attracive option? Or maybe not..., once again I may be saying something stupid....

[thepolarfoxqx]

think about that shift pattern!!! completely filling 4 rows of gates. Yes, but why do you need more than six gears. I have never once gotten in a car with six speeds and felt a need for more. It seems like they'd be doing it just to say theirs had more than someone else.

[GIR]

7 gear manual?! That's going to be like driving a truck! Seriously I don't think I could drive comfortable in a 7 gear manual.

[thepolarfoxqx]

really!!!

it is too much shifting. Hell, in my boxster S, i start in 2nd half the time, and skip straight to 4th, 5th, or 6th.

[izzyloveslizzy]

I smell a challenege here. BMW is likely to make a 7-speed SMG just for the hell of it, to flip the bird at MB.

[thepolarfoxqx]

i think BMW is too wise to just make a 7 speed (which really is NOT needed, six is plenty of ratios) just to best MB. 6 is plenty tall, and 1st is plenty short, and they are really close together. I don't see a need for a 7 speed SMG. Furthermore, Getrag, the manufacturer of manuals for BMW said they don't have nor are making a 7 speed stick, and if there is no gearbox, then BMW can't bolt the SMG on. For now, BMW has 6 speeds.

[GIR]

Well the rumours turned out to be true. Mercedes introduced a 7 speed automatic called 7G-Tronic (what's with the tronic in all the german technology?). This transmisions allows for a smoother ride, better acceleration between 60-120km/h and better mileage. The best tthing about this transmission is that it allows stageless switching, so you could go from 1st to 3th to 4th or in a kickdown from 7th to 5th to 3th.

I guess Mercedes is really out to prove automatics can beat manuals.

[thepolarfoxqx]

that stageless is a very nice feature. 7 speeds is excessive. I think 6 is even pushing it. I wonder how it is weight wise.

[GIR]

Here's some more info:

7G-TRONIC: Mercedes-Benz presents the world’s first seven-speed automatic transmission for passenger cars

Fitted as standard in five eight-cylinder models from autumn 2003

Fuel saving of up to 0.6 litres per 100 kilometres

Even shorter acceleration times and quicker intermediate sprints

Stuttgart, Germany, May 14, 2003

7G-TRONIC from Mercedes-Benz: The word´s first seven-speed automatic-transmission

The world’s first standard-fitted seven-speed automatic transmission for passenger cars will make future Mercedes models even more economical and further boost their acceleration. In addition, the new transmission variant will also considerably enhance shifting comfort still further.

The new 7G-TRONIC seven-speed automatic transmission will be a standard feature of the E 500, S 430, S 500, CL 500 and SL 500 models from autumn 2003, replacing the five-speed automatic version currently fitted.

The newly developed seven-speed automatic transmission reduces fuel consumption in the NEDC driving cycle by as much as 0.6 litres per 100 kilometres (depending on the car), increases acceleration from 0 to 100 km/h by up to 0.3 seconds and allows significantly quicker intermediate sprints from 60 to 120 km/h. At the same time, shifting is even smoother, and therefore more comfortable, than with the automatic transmission presently used.

The Mercedes engineers have achieved these advances above all through the use of seven gear ratios. These allow the automatic transmission to retain the small increases in engine speed which are important in ensuring optimum gear ratios, whilst at the same time offering a larger ratio spread between the lowest and highest gear. This gives the electronic control unit more flexibility to adjust shifting in such as way as to keep fuel consumption low and the transmission’s reactions fast. What’s more, it also lowers the average engine speed – a clear plus point in terms of both cutting fuel consumption and keeping the lid on noise levels.

Fast gear-change using the principle of repeated downshift

When the driver switches down rapidly through the gears (kickdown), the new transmission does not always select the individual gears in strict order. Instead, 7G-TRONIC will miss out a particular gear if necessary, switching from seventh gear straight down to fifth, for example, and from there directly to third. In this situation, only two gear changes are actually required – instead of the normal four – in order to accelerate quickly using kickdown.

Shift quality, meanwhile, also hits new heights. The new transmission glides through the gears extremely smoothly and yet with impressive speed. Gear-change is barely noticeable, especially in the higher gears.

Torque converter lockup from first gear

As in its predecessor, one outstanding feature of the new seven-speed automatic transmission is a lockup clutch in the hydrodynamic torque converter. In many situations, this system largely eliminates slip between the pump and turbine rotor. It does this by establishing a virtually fixed connection wherever possible between the engine shaft and transmission shaft, creating an extremely effective barrier to output loss. In contrast to conventional automatic transmissions, in which torque converter lockup is only possible in higher gears, the lockup clutch in the new seven-speed automatic transmission from Mercedes-Benz is active from the first gear up.

Despite these significant technical advances, the 7G-TRONIC automatic transmission is barely any larger or heavier than the five-speed automatic transmission currently fitted in Mercedes passenger cars. Credit for this impressive achievement goes in particular to the transmission casing, which is constructed in lightweight magnesium – also a world premiere in volume production.

Mercedes has produced eleven million automatic transmissions since 1959

The 7G-TRONIC transmission development represents the fifth generation of automatic transmissions made by the Mercedes-Benz brand, and in so doing continues an impressive tradition. Since 1959, the Stuttgart-based car maker has produced over eleven million automatic transmissions. Whilst the automatic transmission is part of the standard equipment in the S-Class, around 88 percent of all Mercedes E-Class customers currently order their car with automatic transmission, whilst the figure stands at some 65 percent for the C-Class Saloons, Estates and Sports Coupés – and this figure is on the rise.

The new seven-speed automatic transmission will be produced at the Mercedes plant at Stuttgart-Untertürkheim, the original location of the company’s very first production facility. DaimlerChrysler has invested some 400 million euros at the plant in the construction of a new complex of buildings containing state-of-the-art production equipment and installations for around 1100 employees.

[Tsar Kalojan]

7-speed automatic, I read this was made to decrease fuel comsumption...

[Tsar Kalojan]

7-speed automatic, I read this was made to decrease fuel comsumption...

[thepolarfoxqx]

6 wasn't enough?

[GIR]

Well apparently BMW jumped on the 7 speed bandwagon aswell. The E60 M5 will have a manual 7 speed or SMG III which is a 7 speed SMG. The E60 M5 will also have a factory option to remove the limiter, just like the CL65 and the SL65.

BMW has confirmed the option to remove the limiter, Mercedes has announced that they are considering it.

[thepolarfoxqx]

where are you finding 7 speed for E60 M5? I have found numerous articles - some as reliable as edmund's stating a 6spd SMG II - but a 7? Wow.

[GIR]

The creator of bmwm5.com, a guy called Gustav, is rumored to have close contacts in BMW. Anywayz he put the info on the bmwm5.com forums.

http://www.bmwm5.com/vbulletin/showthread.php?s=ddcab0b0310cf7c2c1e8ead0a861c166&threadid=31538

In the past he was correct about similar rumors so I kinda trust him. I guess we'll have to wait and see.

I read the edmunds article aswell, didn't see any reference to a 6speed though, must have missed it. Anywayz it was funny to see how they were discussing tech that MB already had announced. For intance MB is going to have steer-by-wire and a HUD with IR-cams in the mirros and back of the car at the end of this year. The HUD MB is going to use will also have colors and will tie into the cars controls.