Well, that's a great engineering accomplishment. With total
respect, and some understanding about what it takes to make
an overly complicated automatic transmission like that work
when coupled with an efficient torque converter, my
question is, who needs it?
IMO, the current Mercedes engineers should be making
video games or editing digital movies for PIXAR. I can't
imagine why they recently got bought out and why their
latest cars are so nondescript! My father, who was a
very meticuluous oral surgeon bought his last Mercedes
in 1967 and refused to even consider buying another one.
I thought he was a little nuts then, but, my thinking
is probably genetic.
In this current economy, people will SPEND +$50,000 on a
car because their primary interest is SAVING money on
fuel? Oh my God! Who's running this show, Merrill Lynch?
Enron? Arthur Anderson!
Now, reality. Saving .6 liters of fuel in 100 km
on the higher end Mercedes models is meaningless. Who
cares? The depreciation and repair expenses is what
will kill you! You have to be kidding!!! Have you ever
got the bill when one of those sophisticated 7 speed
automatic transmissions XXXXX XX? You fill in the
X's. Trust me, you won't save anything!
Technically and logically you are 100% correct. A 7 speed auto is absolute bull****, but sometimes bull**** baffels brains, especially when it's driven by a marketing team, who honed their skills selling "wiggets", and who have identified a bunch of very wealthy, but not particularly competent snobs as their target market.
Anybody who will pay $50,000, for what is essentially a $20,000 car, just because they like to be seen wearing it's badge, or because they like to be associated with a reputation earned during the last bit of the 19th centry, and the first half of the 20th, is obviously beyond help with regards to logic, so just forget about them, so long as they leave you alone.
However, many will for a que to depart with these large sums of money, if for no other reason than to blatently display that they have money to burn.
They will use the fuel economy excuse to their accountant or shareholders. Scarey isn't it.
I should say, I love German cars. I've owned them for
years. German engineers are some of the best in the world
but, history has shown that sometimes Germans get easily
distracted. (WWI and WWII are good examples)
I love some German cars to, and some French, And some Italian, and one or two British, the occasional American, but mostly, in this day and age, I prefer to own Japanese, for their overall ballance of trouble free, reasonably priced priced, comfortable to luxury motoring
Your scaring me Chumley. I read your post of June 3 and for a minute I thought I might have written it!!! De ja vu in spades! A good 3 to 5 year old MB or whatever (I would rather have 300-M or something like our Lincoln LS) is a better way toward economy, don't ya think?
Pat, what the Japanese have done so well is to take the German effeciency, the French interiors, Italian styling, British engineering and, American money and come up with such things as Lexus, Infinity, etc. Great cars for that market segment that likes to be "seen" to have "money to burn"! Remember I live in SoCal where 'being seen' is more important than 'having'. Ya might be on food stamps but ya just gotta have that 'big screen'!
Different tarrif structures, and different model offerings change that a little here.
I was probably refering to Honda Civics/CRX, Nissan Skyline/Pulsar/Maxima, Toyota Land Cruiser/Corrola/Camry/Cressida.
Also, the Lexus is still considerably cheaper than a comparable Benz over here, but a Maxima has all that most people need, and is certainly easier to own, and the "Luxury" level is more than adequate for the most pampered.
Having just critised MB's 7 speed auto, I find myself promoteing the Maxima, which has a CVT. Just one more bullet hole in the foot
I've been messing about with a gearbox simulator and must agree that up to 100 kph or so on urban driving it is hard to justify more than 4 speeds. However I suspect that for a relatively small investment (to go from 5 to 7 speeds) they have a system that allows them to make block changes while retaining reasonable shift quality. We used to make block changes on our 4 speed but they got banned, it is too hard to calibrate them.
Another way of looking at it is to think about the 0-60 advantage they get from a close ratio box, and compare the investment required in the engine to get the same improvement.
I didn't realise the Maxima has a CVT, I must get hold of one.
I can agree to a certain extend with the mercedes-bashing in the previous posts...indeed marketing here is more dominant then engineering. On the other hand: the transmission will be used in powerful vehicles (electronically limited to 250 km/h) but in fact capable of still higher speeds) driven on motorways where actually those speeds are legal. And the technology developed will no doubt trickle down to less exclusive models and to other makes of cars - as was the case with the safetyfeatures that mercedes developed in the late fifties.
I think this is actually useful, but not for fuel economy. The top Mercedes are now being sold as luxury cars that are also speed demons. Gear ratios would usually be selected very differently for those two applications.
Lets look at the design requirements:
Shift and cruise at low rpm (noise/ smoothness/ fuel economy/ engine wear): tall gears
High speed cruising for Germany: tall top gear
Responsive at low-mid throttle: close ratios
Drag racing: short gears
High speed handling: close ratios (an ill-timed downshift in a wide ratio trans would be very bad in a corner)
There are a lot of compromises in trying to implement all of this even with 5 speeds. 7 would be great. Cars have to be fun as well as functional!
They also say that the torque converter locks in 1st gear on up, making the car feel nearly as responsive as a manual. I normally don't like driving autos, but I think this has a lot of potential.
When I was a kid (not that long ago ...... really), cars had 3 or 4-speed manual or 2 or 3-speed auto transmissions.
Now we have cars with bigger, more powerful, more flexible engines with flatter torque curves thanks to VVT, multi-valves, intake tract design etc. etc.
And yet we have moved to 5 or 6 manual gears, 4 or 5 speed autos - now 7 speed!
I have been working on a road vehicle with 700 hp and a GVW of 120 tonnes. It has an Allison 7-speed auto and needs it. But on a passenger car?
I like playing tunes on a gearbox too. But is this progress?
The current "state of the art" is for the add boys to "create the need" so that the the buying public "demand" a solution (creating a demand?). If it can be perceived as needed then the 7 speed, indeed, whatever 'gizmo', will be snapped up by the buyer. No one ever accused the "buying public" with possesing huge amts of common sense.
Don't count me in on this deal. I am a 'throwback'---I drive a 1930 Ford car, ride a 1948 Norton and, race a 1963 Austin Cooper. I do see, looming on the horizon, the CVT/IVT in the near future.
I agree that right now, a 7 speed auto with a torque converter (a torque converter is really a reasonably restricted CVT) is over engineering.
I also agree that consumers can be shown to have an extreme lack of common sense at times. Tobacco and chewing gum sales for instance, and the cars of the late 50's and early 60's with enormous fins.
However times do change, and as we improve our technology at makeing complex machines cheaper. Also, the relative costs of fuel keeps changing
Yeah, but I have a feeling that if the next mercedes benz press release contains info about some over-engineered 600hp engine, every one of ya would get giddy! Overdone or not, some things are just sexy!
I would wager 85% of M-B shoppers have no clue or care how many speeds are in their AT. The motivation is between the lines of the press release; 1) better 0-60 times being a marketable sales point, and 2) Even marginally better mileage goes into CAFE, where percentages are worth billions to the OEM and shareholders.
Who would've thought a tranny could be so controversial- especially in an engineering forum?!
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