Automakers are spending billions to develop six-, seven- or possibly even eight-speed transmissions, The Wall Street Journal reported.

Why? For better fuel economy and to outdo rivals in a crowded market, the WSJ explained.

For example, Mercedes is moving to offer seven-speed transmissions in most of its new models; Volkswagen’s new Jetta offers a six-speed automatic transmission as an option; Ford will soon offer a six-speed automatic on its Explorer; and Toyota's Lexus brand is working on an eight-speed automatic transmission.

To catch up in the gear wars General Motors is working with Ford on a new, jointly designed six-speed transmission that will start appearing in GM vehicles in 2006. By 2010, GM plans to produce three million six-speed transmissions a year, up from a projected one million by 2008, the WSJ said, citing Tom Stephens, GM's group vice president in charge of worldwide powertrain operations.

But some companies aren't speed shifting to six-speeds. Honda executives say for now they're satisfied with the performance of the company's five-speed automatic transmissions. And Chrysler is just phasing in five-speed automatic transmissions in its popular Chrysler 300C sedan, while its minivans still use four-speed automatics.

Don't you think it's going overboard?





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-----The orginal Mr.Goodwrench on the JBO since 11/99-----

6 speeds is enough.


-Borsty

for some reason it makes me think of semis


Andy

it's not how fast you go, it's how you get there that counts.
ZZP XP cam, 1.6 rockers, 105# springs, speedbuilt FWI, 3.3" modular pulley, TOG headers,
3" exhaust, flomatched injectors
'97 GTP 14.06@100.6mph pre cam w/ 3.5" pulley, I/E

there like 10, 13 ,15 and 18 speeds and the transmissions weigh in excess of 1000 lbs.


-Borsty

i can see it costing an arm and leg to fix them.

... i was kidding


Andy

it's not how fast you go, it's how you get there that counts.
ZZP XP cam, 1.6 rockers, 105# springs, speedbuilt FWI, 3.3" modular pulley, TOG headers,
3" exhaust, flomatched injectors
'97 GTP 14.06@100.6mph pre cam w/ 3.5" pulley, I/E

Heh.

I feel bad for transmission shops. I've seen inside 700R4's (4 spd auto) and I wouldn't know what the hell to do with it, so if I saw inside something that was 2x more complicated, I definitely wouldn't know what to do.

MiKeDiRnTRuLeZ wrote:Heh.

I feel bad for transmission shops. I've seen inside 700R4's (4 spd auto) and I wouldn't know what the hell to do with it, so if I saw inside something that was 2x more complicated, I definitely wouldn't know what to do.

Its called guraranteed profits. Who would want to work on an eight speed tranny, so dealerships here they come.

I can understand that many gears in a Heavy duty truck with a creeper 1st gear to get the load moving and then still have a good gear stack for fuel economy.




Yella02-I promise I will return to you in one piece and this will stay up until I am safely home

also for speed
since they can shift faster than us

have an 8 speed to keep the car in the power band all the time

But how does that help fuel economy? That's where I'm confused, I know about the speed thing that's why performance cars have close-ratio transmissions. But a close Ratio tranny isn't the best for Fuel economy, but a wide-ratio one would, but if you get too many gears then the stack becomes too wide, and you end up lugging the engine in high gear.




Yella02-I promise I will return to you in one piece and this will stay up until I am safely home

you could have a very extreme 8th gear overdrive! lol Imagine 1200 rpm's at 65 mph

Saint wrote:But how does that help fuel economy? That's where I'm confused, I know about the speed thing that's why performance cars have close-ratio transmissions. But a close Ratio tranny isn't the best for Fuel economy, but a wide-ratio one would, but if you get too many gears then the stack becomes too wide, and you end up lugging the engine in high gear.

I am by no means a tranny expert. But couldn't you have say 5 or 6 of those gears really close ratio for speed and the remaing 3 or 2 for overdrive type gears for economy?

That does make sense, and now that I think about it that's what Chrysler did with the 5-45RFE Transmission, Gears 1-3 are normal gears while 4 and 5 are overdrive gears.




Yella02-I promise I will return to you in one piece and this will stay up until I am safely home

FstCavZ24 (Turbo ECO) wrote:

Saint wrote:But how does that help fuel economy? That's where I'm confused, I know about the speed thing that's why performance cars have close-ratio transmissions. But a close Ratio tranny isn't the best for Fuel economy, but a wide-ratio one would, but if you get too many gears then the stack becomes too wide, and you end up lugging the engine in high gear.

I am by no means a tranny expert. But couldn't you have say 5 or 6 of those gears really close ratio for speed and the remaing 3 or 2 for overdrive type gears for economy?

But why would you really need 2 overdrive gears when you could make one enormously tall overdrive gear?

I guess if .00001 MPG is important enough to make another gear, then by all means go for it.

because of the gear spread, if there is too big of a difference it will lug the engine and cause excessive shifting which will create a lot of heat, not that there wouldn't be a lot of shifitng in an 8-spd. auto, but it will allow a gear to be held longer in certain situations.




Yella02-I promise I will return to you in one piece and this will stay up until I am safely home

to quote my folks "the more goodies come with your
car.... the more expenses you'll have down the road."

I'm sure any new car -- with any new innovation -- is
fine as long as its under lease/ dealer warranty... In
other words... as long as its not your problem. I would
hate to a buy a used one, and deal with any of its
mechanical bills/ problems when the warranty expires.





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