7 & 8 speed transmissions

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They've been available for a number of years now. Was there a specific question or concern? The more gears there are, the more opportunity there is to match the correct gear for the current driving condition.
 
Originally Posted By: skyactiv
Where have you been at? There are 10 speed transmissions now.


Yup, LOL!
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I think that beyond a certain point the complexity outweighs the gains. I'd say that 5 or 6 forward speeds is the sweet spot.

A lot of people here, for some reason, tend to refer to the new trannies as 'multigear'. I reply that my three Powerglides were are all multigear, two gear ratios being more than one.
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The technology has been in production since the early 2000's (ZF & Allison) What differs the 5-10 speed autos from the earlier 3 & 4 speeds is the TOTAL electronic control of clutch apply & disengagement via "Trim Solenoids". Gone are the Accumulators, Bands, & Servos.
 
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“I think that beyond a certain point the complexity outweighs the gains. I'd say that 5 or 6 forward speeds is the sweet spot.“


My impression with anything more than 6 or 7 speeds is that it is constantly shifting as the computer is trying to keep the vehicle in the most efficient range. At that point a cvt might as well be in place. This becomes even more apparent going through hills or over mountain passes.
 
Originally Posted By: skyactiv
Where have you been at? There are 10 speed transmissions now.


Standby to be amazed there are 18 speed bikes.
 
Originally Posted By: JohnnyJohnson
Originally Posted By: skyactiv
Where have you been at? There are 10 speed transmissions now.


Standby to be amazed there are 18 speed bikes.


That was the early 90s bud. There are 30 speed drivetrains (3x10) on mountain bikes although the latest trend is a wide ratio 1 x 11 drivetrain.
 
Originally Posted By: PimTac
“I think that beyond a certain point the complexity outweighs the gains. I'd say that 5 or 6 forward speeds is the sweet spot.“


My impression with anything more than 6 or 7 speeds is that it is constantly shifting as the computer is trying to keep the vehicle in the most efficient range. At that point a cvt might as well be in place. This becomes even more apparent going through hills or over mountain passes.
Some of the gears aren't used under normal conditions on some models. I have heard reports of customers complaining that they couldn't achieve 8th gear.
 
Like a lot of changes to modern vehicles, the change is driven by fuel economy requirements.

In years gone by, had a lot of 4 speed sticks. Then it was 4 with electric overdrive, then a true 5. My first 6 speed was a 2013 Jetta TDI. I expected it to be a gimmick. It was not. Mileage was better than my much lighter 5 speed Jetta.

My Jaguar diesel has an 8 speed auto, and it uses all 8 gears. Out on the open road the engine is always running at a speed that gives optimum economy or performance as requested by the driver. It is quieter and faster than the Jetta, and gets better fuel economy. And, it appears that they did not cheat to get it approved.

As for other vehicles, I have driven a 3 axle water tender with a 10 speed manual transmission. It needed it to keep the engine spinning at the optimal speed for efficiency. Actually, to keep the engine spinning at a speed that would move the beast when it was hauling 3000 or more gallons of water.

All of my current mountain bikes use 1X gears. Either 1X10 or 1X11. The outer limit right now seems to be 1X12. My new road bike has 2X11, which replaced an older 2X9 bike.

Is it a gimmick? Not really. My average pedaling rate stays up around 90 on the new bike, which means I am always spinning at my preferred speed. That allows me to ride more comfortably and faster. Very much a win/win.

For all of these, cars, trucks, and bicycles, the only downside is cost. The benefit is increased performance.
 
There used to be 50cc GP motorcycles. They needed the 10 or 12 speed gearboxes because of the narrow powerbands. A few rpm's below the sweet spot in the rev range was like turning the motor off and a few rpm's above the sweet spot which was, in reality, the red line meant an explosion.
 
Originally Posted By: Number_35
I think that beyond a certain point the complexity outweighs the gains. I'd say that 5 or 6 forward speeds is the sweet spot.


I might have agreed with you a few years ago. All 3 of my vehicles have A8 transmissions. They are smooth, shift seamlessly and are a pleasure to drive. My take is that 8 forward speeds is the sweet spot.
 
8 speed ZF's have been in use for many years in Bentley, Jaguar, BMW, etc. Very reliable and durable, no need for fear.

The reason is "ratio spread". The wider the spread the better the performance while still giving excellent economy. This is why our 14 RAM can have 395 hp yet consistently return just shy of 20 mpg.
 
I'll never understand why people freak out over anything new. Reality is you don't even notice it unless you're really looking hard for it. I drove an Equinox recently which turns out has a 9 speed trans and I had literally no idea.

I'd wager people were saying the same things about 3, 4, 5 speed transmissions too.
 
No one mentioned the size of the engine CAN be lowered with an increase in available gear ratios.

The formula was self apparent:
Bigger torque curve engines could use a 2 or 3 speed transmission.
"Little" 4 bangers from Europe needed the 4th and 5th gears.

OD became a "thing". I loved and still love Ford's putting a little D inside an O on the range selector.
Was it Vette's which had "the first" 6 speed trannies?

Upward and onward.
 
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